diff --git a/web/src/beta/ui/fields/TimePointField/EditPanel/hooks.ts b/web/src/beta/ui/fields/TimePointField/EditPanel/hooks.ts
index 082bef65b6..bffac027df 100644
--- a/web/src/beta/ui/fields/TimePointField/EditPanel/hooks.ts
+++ b/web/src/beta/ui/fields/TimePointField/EditPanel/hooks.ts
@@ -1,7 +1,9 @@
 import {
+  type ParsedDateTime,
   getLocalTimezoneOffset,
   isValidDateTimeFormat,
   isValidTimezone,
+  parseDateTime,
   TimeZoneOffset
 } from "@reearth/beta/utils/time";
 import { useCallback, useEffect, useMemo, useState } from "react";
@@ -42,8 +44,9 @@ export default ({ value, onChange, onClose }: Props) => {
 
   useEffect(() => {
     if (value && isValidDateTimeFormat(value)) {
-      const [parsedDate, timeWithOffset] = value.split("T");
-      const [parsedTime, timezoneOffset] = timeWithOffset.split(/[-+]/);
+      //Since isValidDateTimeFormat already validates the input, it's safe to assert the type as ParsedDateTime.
+      const { parsedDate, timeWithOffset, parsedTime, timezoneOffset } =
+        parseDateTime(value) as ParsedDateTime;
 
       setDate(parsedDate);
       setTime(parsedTime);
diff --git a/web/src/beta/ui/fields/TimePointField/index.tsx b/web/src/beta/ui/fields/TimePointField/index.tsx
index e1a84c3a9d..ea31d84c6d 100644
--- a/web/src/beta/ui/fields/TimePointField/index.tsx
+++ b/web/src/beta/ui/fields/TimePointField/index.tsx
@@ -1,4 +1,5 @@
 import { Button, Popup, TextInput } from "@reearth/beta/lib/reearth-ui";
+import { isValidDateTimeFormat } from "@reearth/beta/utils/time";
 import { useT } from "@reearth/services/i18n";
 import { styled, useTheme } from "@reearth/services/theme";
 import { FC, useCallback, useEffect, useState } from "react";
@@ -44,7 +45,9 @@ const TimePointField: FC<TimePointFieldProps> = ({
     (timeString: string) => {
       if (timeString === value) return;
       // TODO: validate timeString
-      onChange?.(timeString);
+      if (timeString && isValidDateTimeFormat(timeString)) {
+        onChange?.(timeString);
+      }
     },
     [value, onChange]
   );
diff --git a/web/src/beta/utils/time.test.ts b/web/src/beta/utils/time.test.ts
index decb14c17b..c3d00867f4 100644
--- a/web/src/beta/utils/time.test.ts
+++ b/web/src/beta/utils/time.test.ts
@@ -1,6 +1,6 @@
-import { describe, test, expect } from "vitest";
+import { describe, test, expect, it } from "vitest";
 
-import { formatRelativeTime } from "./time";
+import { formatRelativeTime, parseDateTime } from "./time";
 
 describe("formatRelativeTime", () => {
   const now = new Date();
@@ -73,3 +73,76 @@ describe("formatRelativeTime", () => {
     expect(formatRelativeTime(date, "ja")).toBe("2年前");
   });
 });
+
+describe("parseDateTime", () => {
+  it.each([
+    [
+      "2024-01-01T12:00Z",
+      {
+        parsedDate: "2024-01-01",
+        timeWithOffset: "12:00Z",
+        parsedTime: "12:00",
+        timezoneOffset: "00:00"
+      }
+    ],
+    [
+      "2024-01-01T12:00:00Z",
+      {
+        parsedDate: "2024-01-01",
+        timeWithOffset: "12:00:00Z",
+        parsedTime: "12:00:00",
+        timezoneOffset: "00:00"
+      }
+    ],
+    [
+      "2024-01-01T12:00:00.123Z",
+      {
+        parsedDate: "2024-01-01",
+        timeWithOffset: "12:00:00.123Z",
+        parsedTime: "12:00:00.123",
+        timezoneOffset: "00:00"
+      }
+    ],
+    [
+      "2024-01-01T12:00+09:00",
+      {
+        parsedDate: "2024-01-01",
+        timeWithOffset: "12:00+09:00",
+        parsedTime: "12:00",
+        timezoneOffset: "09:00"
+      }
+    ],
+    [
+      "2024-01-01T12:00:00+09:00",
+      {
+        parsedDate: "2024-01-01",
+        timeWithOffset: "12:00:00+09:00",
+        parsedTime: "12:00:00",
+        timezoneOffset: "09:00"
+      }
+    ],
+    [
+      "2024-01-01T12:00:00.123+09:00",
+      {
+        parsedDate: "2024-01-01",
+        timeWithOffset: "12:00:00.123+09:00",
+        parsedTime: "12:00:00.123",
+        timezoneOffset: "09:00"
+      }
+    ]
+  ])("should correctly parse %s", (input, expected) => {
+    const result = parseDateTime(input);
+    expect(result).toEqual(expected);
+  });
+
+  it.each([
+    "invalid",
+    "2024-01-01",
+    "2024-01-01T12",
+    "2024-01-01T12:00+9:00",
+    ""
+  ])("should return null for invalid datetime format %s", (input) => {
+    const result = parseDateTime(input);
+    expect(result).toBeNull();
+  });
+});
diff --git a/web/src/beta/utils/time.ts b/web/src/beta/utils/time.ts
index 08f12e6022..e402e40139 100644
--- a/web/src/beta/utils/time.ts
+++ b/web/src/beta/utils/time.ts
@@ -111,5 +111,37 @@ export const getTimeZone = (time: string): TimeZoneOffset | undefined => {
 };
 
 export const isValidDateTimeFormat = (time: string): boolean => {
-  return /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}([-+]\d{2}:\d{2})$/.test(time);
+  return /^(\d{4}-\d{2}-\d{2})T(\d{2}:\d{2}(?::\d{2}(?:\.\d{1,3})?)?)(Z|([+-]\d{2}:\d{2}))?$/.test(
+    time
+  );
+};
+
+export type ParsedDateTime = {
+  parsedDate: string;
+  timeWithOffset: string;
+  parsedTime: string;
+  timezoneOffset: string;
+};
+
+export const parseDateTime = (value: string): ParsedDateTime | null => {
+  const match = value.match(
+    /^(\d{4}-\d{2}-\d{2})T(\d{2}:\d{2}(?::\d{2}(?:\.\d{1,3})?)?)(Z|([+-]\d{2}:\d{2}))?$/
+  );
+
+  if (!match) {
+    return null;
+  }
+
+  const parsedDate = match[1];
+  const timeWithOffset = match[2] + (match[3] || "");
+  const parsedTime = match[2];
+  const timezoneOffset =
+    match[3] === "Z" ? "00:00" : match[3]?.replace("+", "") || "00:00";
+
+  return {
+    parsedDate,
+    timeWithOffset,
+    parsedTime,
+    timezoneOffset
+  };
 };