diff --git a/src/duration.rs b/src/duration.rs
index f00b03663e..098169627e 100644
--- a/src/duration.rs
+++ b/src/duration.rs
@@ -19,24 +19,10 @@ use std::error::Error;
 #[cfg(feature = "rkyv")]
 use rkyv::{Archive, Deserialize, Serialize};
 
-/// The number of nanoseconds in a microsecond.
-const NANOS_PER_MICRO: i32 = 1000;
-/// The number of nanoseconds in a millisecond.
-const NANOS_PER_MILLI: i32 = 1_000_000;
-/// The number of nanoseconds in seconds.
-const NANOS_PER_SEC: i32 = 1_000_000_000;
-/// The number of microseconds per second.
-const MICROS_PER_SEC: i64 = 1_000_000;
-/// The number of milliseconds per second.
-const MILLIS_PER_SEC: i64 = 1000;
-/// The number of seconds in a minute.
-const SECS_PER_MINUTE: i64 = 60;
-/// The number of seconds in an hour.
-const SECS_PER_HOUR: i64 = 3600;
-/// The number of (non-leap) seconds in days.
-const SECS_PER_DAY: i64 = 86_400;
-/// The number of (non-leap) seconds in a week.
-const SECS_PER_WEEK: i64 = 604_800;
+use crate::{
+    MICROS_PER_SEC, MILLIS_PER_SEC, NANOS_PER_MICRO, NANOS_PER_MILLI, NANOS_PER_SEC, SECS_PER_DAY,
+    SECS_PER_HOUR, SECS_PER_MINUTE, SECS_PER_WEEK,
+};
 
 macro_rules! try_opt {
     ($e:expr) => {
@@ -221,7 +207,9 @@ impl Duration {
         }
     }
 
-    /// Returns the number of nanoseconds such that
+    /// Returns the number of nanoseconds in the fractional part of the duration.
+    ///
+    /// This is the number of nanoseconds such that
     /// `subsec_nanos() + num_seconds() * NANOS_PER_SEC` is the total number of
     /// nanoseconds in the duration.
     pub const fn subsec_nanos(&self) -> i32 {
@@ -232,6 +220,24 @@ impl Duration {
         }
     }
 
+    /// Returns the number of microseconds in the fractional part of the duration.
+    ///
+    /// This is the number of microseconds such that
+    /// `subsec_micros() + num_seconds() * MICROS_PER_SEC` is the total number of
+    /// microseconds in the duration.
+    pub const fn subsec_micros(&self) -> i32 {
+        self.subsec_nanos() / NANOS_PER_MICRO
+    }
+
+    /// Returns the number of milliseconds in the fractional part of the duration.
+    ///
+    /// This is the number of milliseconds such that
+    /// `subsec_millis() + num_seconds() * MILLIS_PER_SEC` is the total number of
+    /// milliseconds in the duration.
+    pub const fn subsec_millis(&self) -> i32 {
+        self.subsec_nanos() / NANOS_PER_MILLI
+    }
+
     /// Returns the total number of whole milliseconds in the duration,
     pub const fn num_milliseconds(&self) -> i64 {
         // A proper Duration will not overflow, because MIN and MAX are defined
@@ -647,6 +653,33 @@ mod tests {
         assert_eq!(Duration::days(-i64::MAX / NANOS_PER_DAY - 1).num_nanoseconds(), None);
     }
 
+    #[test]
+    fn test_duration_subsec_nanos() {
+        assert_eq!(Duration::zero().subsec_nanos(), 0);
+        assert_eq!(Duration::nanoseconds(1).subsec_nanos(), 1);
+        assert_eq!(Duration::nanoseconds(-1).subsec_nanos(), -1);
+        assert_eq!(Duration::seconds(1).subsec_nanos(), 0);
+        assert_eq!(Duration::nanoseconds(1_000_000_001).subsec_nanos(), 1);
+    }
+
+    #[test]
+    fn test_duration_subsec_micros() {
+        assert_eq!(Duration::zero().subsec_micros(), 0);
+        assert_eq!(Duration::microseconds(1).subsec_micros(), 1);
+        assert_eq!(Duration::microseconds(-1).subsec_micros(), -1);
+        assert_eq!(Duration::seconds(1).subsec_micros(), 0);
+        assert_eq!(Duration::microseconds(1_000_001).subsec_micros(), 1);
+    }
+
+    #[test]
+    fn test_duration_subsec_millis() {
+        assert_eq!(Duration::zero().subsec_millis(), 0);
+        assert_eq!(Duration::milliseconds(1).subsec_millis(), 1);
+        assert_eq!(Duration::milliseconds(-1).subsec_millis(), -1);
+        assert_eq!(Duration::seconds(1).subsec_millis(), 0);
+        assert_eq!(Duration::milliseconds(1_000_001).subsec_millis(), 1);
+    }
+
     #[test]
     fn test_duration_checked_ops() {
         assert_eq!(
diff --git a/src/lib.rs b/src/lib.rs
index da8e00d17a..ef410f5408 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -585,6 +585,25 @@ pub mod rkyv {
     pub use crate::weekday::ArchivedWeekday;
 }
 
+/// The number of nanoseconds in a microsecond.
+pub const NANOS_PER_MICRO: i32 = 1000;
+/// The number of nanoseconds in a millisecond.
+pub const NANOS_PER_MILLI: i32 = 1_000_000;
+/// The number of nanoseconds in a second.
+pub const NANOS_PER_SEC: i32 = 1_000_000_000;
+/// The number of microseconds in a second.
+pub const MICROS_PER_SEC: i64 = 1_000_000;
+/// The number of milliseconds in a second.
+pub const MILLIS_PER_SEC: i64 = 1000;
+/// The number of seconds in a minute.
+pub const SECS_PER_MINUTE: i64 = 60;
+/// The number of seconds in an hour.
+pub const SECS_PER_HOUR: i64 = 3600;
+/// The number of (non-leap) seconds in a day.
+pub const SECS_PER_DAY: i64 = 86_400;
+/// The number of (non-leap) seconds in a week.
+pub const SECS_PER_WEEK: i64 = 604_800;
+
 /// Out of range error type used in various converting APIs
 #[derive(Clone, Copy, Hash, PartialEq, Eq)]
 pub struct OutOfRange {