diff --git a/docs/examples/widgets/month_calendar.py b/docs/examples/widgets/month_calendar.py
new file mode 100644
index 0000000000..878f3acd87
--- /dev/null
+++ b/docs/examples/widgets/month_calendar.py
@@ -0,0 +1,29 @@
+import datetime
+
+from textual.app import App, ComposeResult
+from textual.binding import Binding
+from textual.widgets import MonthCalendar
+
+
+class MonthCalendarApp(App):
+    CSS = """
+    Screen {
+        align: center middle;
+    }
+    """
+
+    BINDINGS = [
+        Binding("ctrl+s", "toggle_show_other_months"),
+    ]
+
+    def compose(self) -> ComposeResult:
+        yield MonthCalendar(datetime.date(year=2021, month=6, day=3))
+
+    def action_toggle_show_other_months(self) -> None:
+        calendar = self.query_one(MonthCalendar)
+        calendar.show_other_months = not calendar.show_other_months
+
+
+if __name__ == "__main__":
+    app = MonthCalendarApp()
+    app.run()
diff --git a/src/textual/widgets/__init__.py b/src/textual/widgets/__init__.py
index 7036ca44f8..a1c0d1ab00 100644
--- a/src/textual/widgets/__init__.py
+++ b/src/textual/widgets/__init__.py
@@ -29,6 +29,7 @@
     from textual.widgets._log import Log
     from textual.widgets._markdown import Markdown, MarkdownViewer
     from textual.widgets._masked_input import MaskedInput
+    from textual.widgets._month_calendar import MonthCalendar
     from textual.widgets._option_list import OptionList
     from textual.widgets._placeholder import Placeholder
     from textual.widgets._pretty import Pretty
@@ -70,6 +71,7 @@
     "Markdown",
     "MarkdownViewer",
     "MaskedInput",
+    "MonthCalendar",
     "OptionList",
     "Placeholder",
     "Pretty",
diff --git a/src/textual/widgets/__init__.pyi b/src/textual/widgets/__init__.pyi
index aaf2e3b9f4..1be74d5041 100644
--- a/src/textual/widgets/__init__.pyi
+++ b/src/textual/widgets/__init__.pyi
@@ -19,6 +19,7 @@ from ._loading_indicator import LoadingIndicator as LoadingIndicator
 from ._log import Log as Log
 from ._markdown import Markdown as Markdown
 from ._markdown import MarkdownViewer as MarkdownViewer
+from ._month_calendar import MonthCalendar as MonthCalendar
 from ._option_list import OptionList as OptionList
 from ._placeholder import Placeholder as Placeholder
 from ._pretty import Pretty as Pretty
diff --git a/src/textual/widgets/_month_calendar.py b/src/textual/widgets/_month_calendar.py
new file mode 100644
index 0000000000..98b6ba6455
--- /dev/null
+++ b/src/textual/widgets/_month_calendar.py
@@ -0,0 +1,520 @@
+from __future__ import annotations
+
+import calendar
+import datetime
+from typing import Sequence
+
+from rich.text import Text
+
+from textual import on
+from textual.app import ComposeResult
+from textual.binding import Binding
+from textual.coordinate import Coordinate
+from textual.events import Mount
+from textual.message import Message
+from textual.reactive import Reactive
+from textual.widget import Widget
+from textual.widgets import DataTable
+from textual.widgets.data_table import CellDoesNotExist
+
+
+class InvalidWeekdayNumber(Exception):
+    """Exception raised if an invalid weekday number is supplied."""
+
+
+class CalendarGrid(DataTable, inherit_bindings=False):
+    """The grid used internally by the `MonthCalendar` widget for displaying
+    and navigating dates."""
+
+    # TODO: Ideally we want to hide that there's a DataTable underneath the
+    # `MonthCalendar` widget. Is there any mechanism so component classes could be
+    # defined in the parent and substitute the component styles in the child?
+    # For example, allow styling the header using `.month-calendar--header`
+    # rather than `.datatable--header`?
+    DEFAULT_CSS = """
+    CalendarGrid {
+        height: auto;
+        width: auto;
+
+        .datatable--header {
+            background: $surface;
+        }
+    }
+    """
+
+
+class MonthCalendar(Widget):
+    BINDINGS = [
+        Binding("enter", "select_date", "Select date", show=False),
+        Binding("up", "previous_week", "Previous week", show=False),
+        Binding("down", "next_week", "Next week", show=False),
+        Binding("right", "next_day", "Next day", show=False),
+        Binding("left", "previous_day", "Previous day", show=False),
+        Binding("pageup", "previous_month", "Previous month", show=False),
+        Binding("pagedown", "next_month", "Next month", show=False),
+        Binding("ctrl+pageup", "previous_year", "Previous year", show=False),
+        Binding("ctrl+pagedown", "next_year", "Next year", show=False),
+    ]
+    """
+    | Key(s) | Description |
+    | :- | :- |
+    | enter | Select the date under the cursor. |
+    | up | Move to the previous week. |
+    | down | Move to the next week. |
+    | right | Move to the next day.|
+    | left | Move to the previous day. |
+    | pageup | Move to the previous month. |
+    | pagedown | Move to the next month. |
+    | ctrl+pageup | Move to the previous year. |
+    | ctrl+pagedown | Move to the next year. |
+    """
+
+    COMPONENT_CLASSES = {
+        "month-calendar--outside-month",
+    }
+    """
+    | Class | Description |
+    | :- | :- |
+    | `month-calendar--outside-month` | Target the dates outside the current calendar month. |
+    """
+
+    # TODO: min-width?
+    DEFAULT_CSS = """
+    MonthCalendar {
+        height: auto;
+        width: auto;
+        min-height: 7;
+
+        .month-calendar--outside-month {
+            color: gray;
+        }
+    }
+    """
+
+    date: Reactive[datetime.date] = Reactive(datetime.date.today)
+    """The date currently highlighted and sets the displayed month in the
+    calendar."""
+    first_weekday: Reactive[int] = Reactive(0)
+    """The first day of the week in the calendar. Monday is 0 (the default),
+    Sunday is 6."""
+    show_cursor: Reactive[bool] = Reactive(True)
+    """Whether to display a cursor for navigating dates within the calendar."""
+    show_other_months: Reactive[bool] = Reactive(True)
+    """Whether to display dates from other months for a six-week calendar."""
+
+    class DateHighlighted(Message):
+        """Posted by the `MonthCalendar` widget when the cursor moves to
+        highlight a new date.
+
+        Can be handled using `on_month_calendar_date_highlighted` in a subclass
+        of `MonthCalendar` or in a parent node in the DOM.
+        """
+
+        def __init__(
+            self,
+            month_calendar: MonthCalendar,
+            value: datetime.date,
+        ) -> None:
+            super().__init__()
+            self.month_calendar: MonthCalendar = month_calendar
+            """The `MonthCalendar` that sent this message."""
+            self.value: datetime.date = value
+            """The highlighted date."""
+
+        @property
+        def control(self) -> MonthCalendar:
+            """Alias for the `MonthCalendar` that sent this message."""
+            return self.month_calendar
+
+    class DateSelected(Message):
+        """Posted by the `MonthCalendar` widget when a date is selected.
+
+        Can be handled using `on_month_calendar_date_selected` in a subclass
+        of `MonthCalendar` or in a parent node in the DOM.
+        """
+
+        def __init__(
+            self,
+            month_calendar: MonthCalendar,
+            value: datetime.date,
+        ) -> None:
+            super().__init__()
+            self.month_calendar: MonthCalendar = month_calendar
+            """The `MonthCalendar` that sent this message."""
+            self.value: datetime.date = value
+            """The selected date."""
+
+        @property
+        def control(self) -> MonthCalendar:
+            """Alias for the `MonthCalendar` that sent this message."""
+            return self.month_calendar
+
+    def __init__(
+        self,
+        date: datetime.date = datetime.date.today(),
+        *,
+        first_weekday: int = 0,
+        show_cursor: bool = True,
+        show_other_months: bool = True,
+        name: str | None = None,
+        id: str | None = None,
+        classes: str | None = None,
+        disabled: bool = False,
+    ) -> None:
+        """Initialize a MonthCalendar widget.
+
+        Args:
+            date: The initial date to be highlighted (if `show_cursor` is True)
+                and sets the displayed month in the calendar. Defaults to today
+                if not supplied.
+            first_weekday: The first day of the week in the calendar.
+                Monday is 0 (the default), Sunday is 6.
+            show_cursor: Whether to display a cursor for navigating dates within
+                the calendar.
+            show_other_months: Whether to display dates from other months for
+                a six-week calendar.
+            name: The name of the widget.
+            id: The ID of the widget in the DOM.
+            classes: The CSS classes of the widget.
+            disabled: Whether the widget is disabled or not.
+        """
+        super().__init__(name=name, id=id, classes=classes, disabled=disabled)
+        self.date = date
+        self.first_weekday = first_weekday
+        self._calendar = calendar.Calendar(first_weekday)
+        """A `Calendar` object from Python's `calendar` module used for
+        preparing the calendar data for this widget."""
+        self.show_cursor = show_cursor
+        self.show_other_months = show_other_months
+        self._calendar_dates = self._get_calendar_dates()
+        """The matrix of `datetime.date` objects for this month calendar, where
+        each row represents a week. See the `_get_calendar_dates` method for
+        details."""
+
+    def compose(self) -> ComposeResult:
+        yield CalendarGrid(show_cursor=self.show_cursor)
+
+    @on(CalendarGrid.CellHighlighted)
+    def _on_calendar_grid_cell_highlighted(
+        self,
+        event: CalendarGrid.CellHighlighted,
+    ) -> None:
+        """Post a `DateHighlighted` message when a date cell is highlighted in
+        the calendar grid."""
+        event.stop()
+        if not self.show_other_months and event.value is None:
+            # TODO: This handling of blank cells is obviously a bit hacky.
+            # Instead this widget should prevent highlighting a blank cell
+            # altogether, either with the keyboard or mouse.
+            calendar_grid = self.query_one(CalendarGrid)
+            date_coordinate = self._get_date_coordinate(self.date)
+            with self.prevent(CalendarGrid.CellHighlighted):
+                calendar_grid.cursor_coordinate = date_coordinate
+        else:
+            cursor_row, cursor_column = event.coordinate
+            new_date = self._calendar_dates[cursor_row][cursor_column]
+            assert isinstance(new_date, datetime.date)
+            # Avoid possible race condition by setting the `date` reactive
+            # without invoking the watcher. When mashing the arrow keys, this
+            # otherwise would cause the app to lag or freeze entirely.
+            old_date = self.date
+            self.set_reactive(MonthCalendar.date, new_date)
+            if (new_date.month != old_date.month) or (new_date.year != old_date.year):
+                self._calendar_dates = self._get_calendar_dates()
+                self._update_calendar_grid(update_week_header=False)
+
+            self.post_message(MonthCalendar.DateHighlighted(self, self.date))
+
+    @on(CalendarGrid.CellSelected)
+    def _on_calendar_grid_cell_selected(
+        self,
+        event: CalendarGrid.CellSelected,
+    ) -> None:
+        """Post a `DateSelected` message when a date cell is selected in
+        the calendar grid."""
+        event.stop()
+        if not self.show_other_months and event.value is None:
+            calendar_grid = self.query_one(CalendarGrid)
+            calendar_grid._show_hover_cursor = False
+            return
+        # We cannot rely on the `event.coordinate` for the selected date,
+        # as selecting a date from the previous or next month will update the
+        # calendar to bring that entire month into view and the date at this
+        # co-ordinate will have changed! Thankfully it is safe to instead
+        # simply use the calendar `date`, as clicking a table cell will emit a
+        # `CellHighlighted` message *before* the `CellSelected` message.
+        self.post_message(MonthCalendar.DateSelected(self, self.date))
+
+    @on(CalendarGrid.HeaderSelected)
+    def _on_calendar_grid_header_selected(
+        self,
+        event: CalendarGrid.HeaderSelected,
+    ) -> None:
+        """Stop the propagation of the `HeaderSelected` message from the
+        underlying `DataTable`. Currently the `MonthCalendar` does not post its
+        own message when the header is selected as there doesn't seem any
+        practical purpose, but this could be easily added in future if needed."""
+        event.stop()
+        pass
+
+    def previous_month(self) -> None:
+        """Move to the previous month."""
+        year = self.date.year
+        month = self.date.month - 1
+        if month < 1:
+            year -= 1
+            month += 12
+        day = min(self.date.day, calendar.monthrange(year, month)[1])
+        self.date = datetime.date(year, month, day)
+
+    def next_month(self) -> None:
+        """Move to the next month."""
+        year = self.date.year
+        month = self.date.month + 1
+        if month > 12:
+            year += 1
+            month -= 12
+        day = min(self.date.day, calendar.monthrange(year, month)[1])
+        self.date = datetime.date(year, month, day)
+
+    def previous_year(self) -> None:
+        """Move to the previous year."""
+        year = self.date.year - 1
+        month = self.date.month
+        day = min(self.date.day, calendar.monthrange(year, month)[1])
+        self.date = datetime.date(year, month, day)
+
+    def next_year(self) -> None:
+        """Move to the next year."""
+        year = self.date.year + 1
+        month = self.date.month
+        day = min(self.date.day, calendar.monthrange(year, month)[1])
+        self.date = datetime.date(year, month, day)
+
+    def _on_mount(self, _: Mount) -> None:
+        self._update_calendar_grid(update_week_header=True)
+
+        def hide_hover_cursor_if_blank_cell(hover_coordinate: Coordinate) -> None:
+            calendar_grid = self.query_one(CalendarGrid)
+            try:
+                hover_cell_value = calendar_grid.get_cell_at(hover_coordinate)
+            except CellDoesNotExist:
+                calendar_grid._set_hover_cursor(False)
+                return
+            if hover_cell_value is None:
+                calendar_grid._set_hover_cursor(False)
+
+        self.watch(
+            self.query_one(CalendarGrid),
+            "hover_coordinate",
+            hide_hover_cursor_if_blank_cell,
+        )
+
+    def _update_calendar_grid(self, update_week_header: bool) -> None:
+        """Update the grid to display the dates of the current month calendar.
+        If specified, this will also update the weekday names in the header.
+
+        Args:
+            update_week_header: Whether the weekday names in the header should
+                be updated (e.g. following a change to the `first_weekday`).
+        """
+        calendar_grid = self.query_one(CalendarGrid)
+        old_hover_coordinate = calendar_grid.hover_coordinate
+        calendar_grid.clear()
+
+        if update_week_header:
+            old_columns = calendar_grid.columns.copy()
+            for old_column in old_columns:
+                calendar_grid.remove_column(old_column)
+
+            day_names = calendar.day_abbr
+            for day in self._calendar.iterweekdays():
+                calendar_grid.add_column(day_names[day])
+
+        with self.prevent(CalendarGrid.CellHighlighted):
+            for week in self._calendar_dates:
+                calendar_grid.add_row(
+                    *[
+                        self._format_day(date) if date is not None else None
+                        for date in week
+                    ]
+                )
+
+        date_coordinate = self._get_date_coordinate(self.date)
+        calendar_grid.cursor_coordinate = date_coordinate
+
+        calendar_grid.hover_coordinate = old_hover_coordinate
+
+    def _format_day(self, date: datetime.date) -> Text:
+        """Format a date for display in the calendar.
+
+        Args:
+            date: The date to format for display in the calendar.
+
+        Returns:
+            A Rich Text object containing the day.
+        """
+        formatted_day = Text(str(date.day), justify="center")
+        if date.month != self.date.month:
+            outside_month_style = self.get_component_rich_style(
+                "month-calendar--outside-month", partial=True
+            )
+            formatted_day.stylize(outside_month_style)
+        return formatted_day
+
+    def _get_calendar_dates(self) -> list[Sequence[datetime.date | None]]:
+        """Returns a matrix of `datetime.date` objects for this month calendar,
+        where each row represents a week. If `show_other_months` is True, this
+        returns a six-week calendar including dates from the previous and next
+        month. If `show_other_months` is False, only weeks required for the
+        month are included and any dates outside the month are 'None'."""
+
+        month_weeks = self._calendar.monthdatescalendar(self.date.year, self.date.month)
+        calendar_dates: list[Sequence[datetime.date | None]]
+
+        if not self.show_other_months:
+            calendar_dates = [
+                [date if date.month == self.date.month else None for date in week]
+                for week in month_weeks
+            ]
+            return calendar_dates
+
+        calendar_dates = [list(week) for week in month_weeks]
+
+        if len(calendar_dates) < 6:
+            previous_month_weeks = self._get_previous_month_weeks()
+            next_month_weeks = self._get_next_month_weeks()
+
+            current_first_date = calendar_dates[0][0]
+            assert isinstance(current_first_date, datetime.date)
+            current_last_date = calendar_dates[-1][6]
+            assert isinstance(current_last_date, datetime.date)
+
+            if len(calendar_dates) == 4:
+                calendar_dates = (
+                    [previous_month_weeks[-1]] + calendar_dates + [next_month_weeks[0]]
+                )
+            elif current_first_date.day == 1:
+                calendar_dates = [previous_month_weeks[-1]] + calendar_dates
+            elif current_last_date.month == self.date.month:
+                calendar_dates = calendar_dates + [next_month_weeks[0]]
+            else:
+                calendar_dates = calendar_dates + [next_month_weeks[1]]
+
+        assert len(calendar_dates) == 6
+
+        return calendar_dates
+
+    def _get_previous_month_weeks(self) -> list[list[datetime.date]]:
+        """Returns a matrix of `datetime.date` objects for the previous month,
+        used by the `_get_calendar_dates` method."""
+        previous_month = self.date.month - 1
+        previous_month_year = self.date.year
+        if previous_month < 1:
+            previous_month_year -= 1
+            previous_month += 12
+        return self._calendar.monthdatescalendar(previous_month_year, previous_month)
+
+    def _get_next_month_weeks(self) -> list[list[datetime.date]]:
+        """Returns a matrix of `datetime.date` objects for the next month,
+        used by the `_get_calendar_dates` method."""
+        next_month = self.date.month + 1
+        next_month_year = self.date.year
+        if next_month > 12:
+            next_month_year += 1
+            next_month -= 12
+        return self._calendar.monthdatescalendar(next_month_year, next_month)
+
+    def _get_date_coordinate(self, date: datetime.date) -> Coordinate:
+        """Get the coordinate in the calendar grid for a specified date.
+
+        Args:
+            date: The date for which to find the corresponding coordinate.
+
+        Returns:
+            The coordinate in the calendar grid for the specified date.
+
+        Raises:
+            ValueError: If the date is out of range for the current month calendar.
+        """
+        for week_index, week in enumerate(self._calendar_dates):
+            if date in week:
+                return Coordinate(week_index, week.index(date))
+
+        raise ValueError("Date is out of range for the current month calendar.")
+
+    def validate_first_weekday(self, first_weekday: int) -> int:
+        if not 0 <= first_weekday <= 6:
+            raise InvalidWeekdayNumber(
+                "Weekday number must be between 0 (Monday) and 6 (Sunday)."
+            )
+        return first_weekday
+
+    def watch_date(self, old_date: datetime.date, new_date: datetime.date) -> None:
+        if not self.is_mounted:
+            return
+        if (new_date.month != old_date.month) or (new_date.year != old_date.year):
+            self._calendar_dates = self._get_calendar_dates()
+            self._update_calendar_grid(update_week_header=False)
+        else:
+            calendar_grid = self.query_one(CalendarGrid)
+            cursor_row, cursor_column = calendar_grid.cursor_coordinate
+            if self._calendar_dates[cursor_row][cursor_column] != new_date:
+                date_coordinate = self._get_date_coordinate(self.date)
+                calendar_grid.cursor_coordinate = date_coordinate
+
+    def watch_first_weekday(self) -> None:
+        self._calendar = calendar.Calendar(self.first_weekday)
+        self._calendar_dates = self._get_calendar_dates()
+        if not self.is_mounted:
+            return
+        self._update_calendar_grid(update_week_header=True)
+
+    def watch_show_cursor(self, show_cursor: bool) -> None:
+        if not self.is_mounted:
+            return
+        calendar_grid = self.query_one(CalendarGrid)
+        calendar_grid.show_cursor = show_cursor
+
+    def watch_show_other_months(self) -> None:
+        self._calendar_dates = self._get_calendar_dates()
+        if not self.is_mounted:
+            return
+        self._update_calendar_grid(update_week_header=False)
+
+    def action_select_date(self) -> None:
+        """Select the date under the cursor."""
+        calendar_grid = self.query_one(CalendarGrid)
+        calendar_grid.action_select_cursor()
+
+    def action_previous_day(self) -> None:
+        """Move to the previous day."""
+        self.date -= datetime.timedelta(days=1)
+
+    def action_next_day(self) -> None:
+        """Move to the next day."""
+        self.date += datetime.timedelta(days=1)
+
+    def action_previous_week(self) -> None:
+        """Move to the previous week."""
+        self.date -= datetime.timedelta(weeks=1)
+
+    def action_next_week(self) -> None:
+        """Move to the next week."""
+        self.date += datetime.timedelta(weeks=1)
+
+    def action_previous_month(self) -> None:
+        """Move to the previous month."""
+        self.previous_month()
+
+    def action_next_month(self) -> None:
+        """Move to the next month."""
+        self.next_month()
+
+    def action_previous_year(self) -> None:
+        """Move to the previous year."""
+        self.previous_year()
+
+    def action_next_year(self) -> None:
+        """Move to the next year."""
+        self.next_year()
diff --git a/src/textual/widgets/month_calendar.py b/src/textual/widgets/month_calendar.py
new file mode 100644
index 0000000000..8c5fcb4967
--- /dev/null
+++ b/src/textual/widgets/month_calendar.py
@@ -0,0 +1,5 @@
+from ._month_calendar import InvalidWeekdayNumber
+
+__all__ = [
+    "InvalidWeekdayNumber",
+]
diff --git a/tests/test_month_calendar.py b/tests/test_month_calendar.py
new file mode 100644
index 0000000000..adadb7ca8f
--- /dev/null
+++ b/tests/test_month_calendar.py
@@ -0,0 +1,562 @@
+from __future__ import annotations
+
+import datetime
+
+import pytest
+
+from textual import on
+from textual.app import App, ComposeResult
+from textual.coordinate import Coordinate
+from textual.widgets import MonthCalendar
+from textual.widgets._month_calendar import CalendarGrid
+from textual.widgets.month_calendar import InvalidWeekdayNumber
+
+
+def test_invalid_month_raises_exception():
+    with pytest.raises(ValueError):
+        _ = MonthCalendar(datetime.date(year=2021, month=13, day=3))
+
+
+def test_invalid_day_raises_exception():
+    with pytest.raises(ValueError):
+        _ = MonthCalendar(datetime.date(year=2021, month=6, day=32))
+
+
+def test_invalid_weekday_number_raises_exception():
+    with pytest.raises(InvalidWeekdayNumber):
+        _ = MonthCalendar(first_weekday=7)
+
+
+def test_calendar_dates_property():
+    month_calendar = MonthCalendar(datetime.date(year=2021, month=6, day=3))
+    first_monday = datetime.date(2021, 5, 31)
+
+    expected_date = first_monday
+    for week in range(len(month_calendar._calendar_dates)):
+        for day in range(0, 7):
+            assert month_calendar._calendar_dates[week][day] == expected_date
+            expected_date += datetime.timedelta(days=1)
+
+
+def test_get_date_coordinate():
+    month_calendar = MonthCalendar(datetime.date(year=2021, month=6, day=3))
+    target_date = datetime.date(2021, 6, 3)
+
+    actual_coordinate = month_calendar._get_date_coordinate(target_date)
+
+    expected_coordinate = Coordinate(0, 3)
+    assert actual_coordinate == expected_coordinate
+
+
+def test_get_date_coordinate_when_out_of_range_raises_exception():
+    month_calendar = MonthCalendar(datetime.date(year=2021, month=6, day=3))
+
+    with pytest.raises(ValueError):
+        month_calendar._get_date_coordinate(datetime.date(2021, 1, 1))
+
+
+async def test_calendar_defaults_to_today_if_no_date_provided():
+    class TodayCalendarApp(App):
+        def compose(self) -> ComposeResult:
+            yield MonthCalendar()
+
+    app = TodayCalendarApp()
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        today = datetime.date.today()
+        assert month_calendar.date == today
+        assert calendar_grid.get_cell_at(calendar_grid.cursor_coordinate).plain == str(
+            today.day
+        )
+
+
+class MonthCalendarApp(App):
+    def __init__(
+        self,
+        date: datetime.date,
+        show_other_months: bool = True,
+    ) -> None:
+        super().__init__()
+        self._date = date
+        self._show_other_months = show_other_months
+        self.messages: list[tuple[str, datetime.date]] = []
+
+    def compose(self) -> ComposeResult:
+        yield MonthCalendar(
+            date=self._date,
+            show_other_months=self._show_other_months,
+        )
+
+    @on(MonthCalendar.DateHighlighted)
+    @on(MonthCalendar.DateSelected)
+    def record(
+        self,
+        event: MonthCalendar.DateHighlighted | MonthCalendar.DateSelected,
+    ) -> None:
+        self.messages.append((event.__class__.__name__, event.value))
+
+
+async def test_calendar_grid_week_header():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        actual_labels = [col.label.plain for col in calendar_grid.columns.values()]
+        expected_labels = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
+        assert actual_labels == expected_labels
+
+
+async def test_calendar_grid_days():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        for row, week in enumerate(month_calendar._calendar_dates):
+            for column, date in enumerate(week):
+                actual_day = calendar_grid.get_cell_at(Coordinate(row, column)).plain
+                assert isinstance(date, datetime.date)
+                expected_day = str(date.day)
+                assert actual_day == expected_day
+
+
+async def test_calendar_grid_after_reactive_date_change_to_different_month():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        month_calendar.date = datetime.date(year=2022, month=10, day=2)
+
+        assert calendar_grid.get_cell_at(calendar_grid.cursor_coordinate).plain == "2"
+        expected_first_monday = datetime.date(2022, 9, 26)
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "26"
+
+
+async def test_calendar_grid_after_reactive_date_change_within_same_month():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        month_calendar.date = datetime.date(year=2021, month=6, day=19)
+
+        assert calendar_grid.get_cell_at(calendar_grid.cursor_coordinate).plain == "19"
+        expected_first_monday = datetime.date(2021, 5, 31)
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "31"
+
+
+async def test_calendar_grid_after_reactive_first_weekday_change():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        # Change first weekday to Sunday
+        month_calendar.first_weekday = 6
+
+        actual_labels = [col.label.plain for col in calendar_grid.columns.values()]
+        expected_labels = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"]
+        assert actual_labels == expected_labels
+        assert calendar_grid.get_cell_at(calendar_grid.cursor_coordinate).plain == "3"
+        expected_first_sunday = datetime.date(2021, 5, 30)
+        actual_first_sunday = month_calendar._calendar_dates[0][0]
+        assert actual_first_sunday == expected_first_sunday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "30"
+
+
+async def test_show_cursor():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+        assert calendar_grid.show_cursor is True  # Sanity check
+
+        month_calendar.show_cursor = False
+
+        assert calendar_grid.show_cursor is False
+
+
+async def test_previous_year():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        month_calendar.previous_year()
+
+        expected_date = datetime.date(2020, 6, 3)
+        assert month_calendar.date == expected_date
+        assert calendar_grid.get_cell_at(calendar_grid.cursor_coordinate).plain == "3"
+        expected_first_monday = datetime.date(2020, 5, 25)
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "25"
+
+
+async def test_next_year():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        month_calendar.next_year()
+
+        expected_date = datetime.date(2022, 6, 3)
+        assert month_calendar.date == expected_date
+        assert calendar_grid.get_cell_at(calendar_grid.cursor_coordinate).plain == "3"
+        expected_first_monday = datetime.date(2022, 5, 30)
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "30"
+
+
+async def test_previous_year_accounts_for_leap_years():
+    app = MonthCalendarApp(date=datetime.date(2024, 2, 29))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+
+        month_calendar.previous_year()
+
+        expected_date = datetime.date(2023, 2, 28)
+        assert month_calendar.date == expected_date
+
+
+async def test_next_year_accounts_for_leap_years():
+    app = MonthCalendarApp(date=datetime.date(2024, 2, 29))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+
+        month_calendar.next_year()
+
+        expected_date = datetime.date(2025, 2, 28)
+        assert month_calendar.date == expected_date
+
+
+async def test_previous_month():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        month_calendar.previous_month()
+
+        expected_date = datetime.date(2021, 5, 3)
+        assert month_calendar.date == expected_date
+        assert calendar_grid.get_cell_at(calendar_grid.cursor_coordinate).plain == "3"
+        expected_first_monday = datetime.date(2021, 4, 26)
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "26"
+
+
+async def test_previous_month_when_month_is_january():
+    app = MonthCalendarApp(date=datetime.date(2021, 1, 1))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        month_calendar.previous_month()
+
+        expected_date = datetime.date(2020, 12, 1)
+        assert month_calendar.date == expected_date
+        assert calendar_grid.get_cell_at(calendar_grid.cursor_coordinate).plain == "1"
+        expected_first_monday = datetime.date(2020, 11, 30)
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "30"
+
+
+async def test_previous_month_accounts_for_leap_years():
+    app = MonthCalendarApp(date=datetime.date(2024, 3, 29))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+
+        month_calendar.previous_month()
+
+        expected_date = datetime.date(2024, 2, 29)
+        assert month_calendar.date == expected_date
+
+
+async def test_previous_month_accounts_for_nonleap_years():
+    app = MonthCalendarApp(date=datetime.date(2021, 3, 29))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+
+        month_calendar.previous_month()
+
+        expected_date = datetime.date(2021, 2, 28)
+        assert month_calendar.date == expected_date
+
+
+async def test_next_month():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        month_calendar.next_month()
+
+        expected_date = datetime.date(2021, 7, 3)
+        assert month_calendar.date == expected_date
+        assert calendar_grid.get_cell_at(calendar_grid.cursor_coordinate).plain == "3"
+        expected_first_monday = datetime.date(2021, 6, 28)
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "28"
+
+
+async def test_next_month_when_month_is_december():
+    app = MonthCalendarApp(date=datetime.date(2021, 12, 1))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        month_calendar.next_month()
+
+        expected_date = datetime.date(2022, 1, 1)
+        assert month_calendar.date == expected_date
+        assert calendar_grid.get_cell_at(calendar_grid.cursor_coordinate).plain == "1"
+        expected_first_monday = datetime.date(2021, 12, 27)
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "27"
+
+
+async def test_next_month_accounts_for_leap_years():
+    app = MonthCalendarApp(date=datetime.date(2024, 1, 29))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+
+        month_calendar.next_month()
+
+        expected_date = datetime.date(2024, 2, 29)
+        assert month_calendar.date == expected_date
+
+
+async def test_next_month_accounts_for_nonleap_years():
+    app = MonthCalendarApp(date=datetime.date(2021, 1, 29))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+
+        month_calendar.next_month()
+
+        expected_date = datetime.date(2021, 2, 28)
+        assert month_calendar.date == expected_date
+
+
+async def test_cell_highlighted_updates_date():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+
+        await pilot.press("right")
+        expected_date = datetime.date(2021, 6, 4)
+        assert month_calendar.date == expected_date
+
+        await pilot.press("down")
+        expected_date = datetime.date(2021, 6, 11)
+        assert month_calendar.date == expected_date
+
+        await pilot.press("left")
+        expected_date = datetime.date(2021, 6, 10)
+        assert month_calendar.date == expected_date
+
+
+async def test_hover_coordinate_persists_after_month_changes():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+        await pilot.hover(MonthCalendar, offset=(3, 3))
+        expected_coordinate = Coordinate(2, 0)
+        assert calendar_grid.hover_coordinate == expected_coordinate  # Sanity check
+
+        month_calendar.date = datetime.date(year=2022, month=10, day=2)
+
+        assert calendar_grid.hover_coordinate == expected_coordinate
+
+
+async def test_hover_coordinate_persists_after_first_weekday_changes():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+        await pilot.hover(MonthCalendar, offset=(3, 3))
+        expected_coordinate = Coordinate(2, 0)
+        assert calendar_grid.hover_coordinate == expected_coordinate  # Sanity check
+
+        month_calendar.first_weekday = 6  # Sunday
+
+        assert calendar_grid.hover_coordinate == expected_coordinate
+
+
+async def test_calendar_updates_when_up_key_pressed_on_first_row():
+    """Pressing the `up` key when the cursor is on the first row should update
+    the date to the previous week and bring that month into view"""
+
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+        assert calendar_grid.cursor_coordinate == Coordinate(0, 3)  # Sanity check
+
+        await pilot.press("up")
+
+        expected_date = datetime.date(2021, 5, 27)
+        assert month_calendar.date == expected_date
+        assert calendar_grid.cursor_coordinate == Coordinate(4, 3)
+        expected_first_monday = datetime.date(2021, 4, 26)
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "26"
+
+
+async def test_calendar_updates_when_down_key_pressed_on_last_row():
+    """Pressing the `down` key when the cursor is on the last row should update
+    the date to the next week and bring that month into view"""
+
+    app = MonthCalendarApp(date=datetime.date(2021, 5, 31))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+        assert calendar_grid.cursor_coordinate == Coordinate(5, 0)  # Sanity check
+
+        await pilot.press("down")
+
+        expected_date = datetime.date(2021, 6, 7)
+        assert month_calendar.date == expected_date
+        assert calendar_grid.cursor_coordinate == Coordinate(1, 0)
+        expected_first_monday = datetime.date(2021, 5, 31)
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "31"
+
+
+async def test_cursor_wraps_around_to_previous_or_next_date():
+    """Pressing the `left`/`right` key when the cursor is on the first/last
+    column should wrap around the cursor to the previous/next date"""
+
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 6))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+        assert calendar_grid.cursor_coordinate == Coordinate(0, 6)  # Sanity check
+
+        await pilot.press("right")
+        assert month_calendar.date == datetime.date(2021, 6, 7)
+        assert calendar_grid.cursor_coordinate == Coordinate(1, 0)
+
+        await pilot.press("left")
+        assert month_calendar.date == datetime.date(2021, 6, 6)
+        assert calendar_grid.cursor_coordinate == Coordinate(0, 6)
+
+
+async def test_calendar_updates_when_date_outside_month_highlighted():
+    """Highlighting a date from the previous or next month should update the
+    calendar to bring that entire month into view"""
+
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 1))
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+        # Sanity checks
+        assert calendar_grid.cursor_coordinate == Coordinate(0, 1)
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "31"
+
+        await pilot.press("left")
+
+        expected_date = datetime.date(2021, 5, 31)
+        assert month_calendar.date == expected_date
+        assert calendar_grid.cursor_coordinate == Coordinate(5, 0)
+        expected_first_monday = datetime.date(2021, 4, 26)
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)).plain == "26"
+
+
+async def test_calendar_if_show_other_months_is_false():
+    """If `show_other_months` is False, only dates from the current month
+    should be displayed and other blank cells should not be selectable"""
+
+    app = MonthCalendarApp(
+        date=datetime.date(2021, 6, 1),
+        show_other_months=False,
+    )
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        expected_messages = [("DateHighlighted", datetime.date(2021, 6, 1))]
+        expected_coordinate = Coordinate(0, 1)
+        expected_date = datetime.date(2021, 6, 1)
+        expected_first_monday = None
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)) == expected_first_monday
+        assert month_calendar.date == expected_date
+        assert calendar_grid.cursor_coordinate == expected_coordinate
+        assert app.messages == expected_messages
+
+        await pilot.click(MonthCalendar, offset=(3, 1))
+        assert calendar_grid.cursor_coordinate == expected_coordinate
+        assert app.messages == expected_messages
+        assert month_calendar.date == expected_date
+
+        await pilot.hover(MonthCalendar, offset=(3, 1))
+        assert calendar_grid._show_hover_cursor is False
+
+
+async def test_calendar_after_reactive_show_other_months_change():
+    app = MonthCalendarApp(
+        date=datetime.date(2021, 6, 1),
+        show_other_months=True,
+    )
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+        calendar_grid = month_calendar.query_one(CalendarGrid)
+
+        month_calendar.show_other_months = False
+
+        expected_first_monday = None
+        actual_first_monday = month_calendar._calendar_dates[0][0]
+        assert actual_first_monday == expected_first_monday
+        assert calendar_grid.get_cell_at(Coordinate(0, 0)) is None
+
+
+async def test_month_calendar_message_emission():
+    app = MonthCalendarApp(date=datetime.date(2021, 6, 3))
+    expected_messages = []
+    async with app.run_test() as pilot:
+        month_calendar = pilot.app.query_one(MonthCalendar)
+
+        expected_messages.append(("DateHighlighted", datetime.date(2021, 6, 3)))
+        assert app.messages == expected_messages
+
+        await pilot.press("enter")
+        expected_messages.append(("DateSelected", datetime.date(2021, 6, 3)))
+        assert app.messages == expected_messages
+
+        await pilot.press("right")
+        expected_messages.append(("DateHighlighted", datetime.date(2021, 6, 4)))
+        assert app.messages == expected_messages
+
+        await pilot.click(MonthCalendar, offset=(2, 1))
+        expected_messages.append(("DateHighlighted", datetime.date(2021, 5, 31)))
+        expected_messages.append(("DateSelected", datetime.date(2021, 5, 31)))
+        # TODO: This probably shouldn't emit another DateHighlighted message?
+        expected_messages.append(("DateHighlighted", datetime.date(2021, 5, 31)))
+        assert app.messages == expected_messages
+
+        month_calendar.previous_month()
+        await pilot.pause()
+        expected_messages.append(("DateHighlighted", datetime.date(2021, 4, 30)))
+        assert app.messages == expected_messages