1 files changed, 31 insertions, 0 deletions
diff --git a/third_party/rust/time/src/util.rs b/third_party/rust/time/src/util.rs
new file mode 100644
index 0000000000..11330501ca
--- /dev/null
+++ b/third_party/rust/time/src/util.rs
@@ -0,0 +1,31 @@
+//! Utility functions.
+
+pub use time_core::util::{days_in_year, is_leap_year, weeks_in_year};
+
+use crate::Month;
+
+/// Whether to adjust the date, and in which direction. Useful when implementing arithmetic.
+pub(crate) enum DateAdjustment {
+    /// The previous day should be used.
+    Previous,
+    /// The next day should be used.
+    Next,
+    /// The date should be used as-is.
+    None,
+}
+
+/// Get the number of days in the month of a given year.
+///
+/// ```rust
+/// # use time::{Month, util};
+/// assert_eq!(util::days_in_year_month(2020, Month::February), 29);
+/// ```
+pub const fn days_in_year_month(year: i32, month: Month) -> u8 {
+    use Month::*;
+    match month {
+        January | March | May | July | August | October | December => 31,
+        April | June | September | November => 30,
+        February if is_leap_year(year) => 29,
+        February => 28,
+    }
+}