diff --git a/src/template/day.rs b/src/template/day.rs
--- a/src/template/day.rs
+++ b/src/template/day.rs
@@ -31,9 +31,12 @@ impl Day {
 Some(Self(day))
 }
 
- // Not part of the public API
- #[doc(hidden)]
- pub const fn __new_unchecked(day: u8) -> Self {
+ /// Creates a new day without checking if it's in the valid range.
+ ///
+ /// # Safety
+ ///
+ /// Ensure that day is in range `1..=24`.
+ pub const unsafe fn new_unchecked(day: u8) -> Self {
 Self(day)
 }
 
@@ -146,7 +149,7 @@ macro_rules! day {
 "`, expecting a value between 1 and 25"
 ),
 );
- $crate::template::Day::__new_unchecked($day)
+ unsafe { $crate::template::Day::new_unchecked($day) }
 }};
 }