implement week support in start_of()/end_of() (#331)

Author: ariebovenberg

CHANGELOG.md

@@ -7,6 +7,9 @@
   This was achieved by deferring the import of several internal submodules
   and timezone database setup until they are actually needed.
 - Fixed CI compatibility with Python 3.13t (free-threaded build)
+- Added ``"week_mon"`` and ``"week_sun"`` as valid
+  units for ``start_of()`` and ``end_of()`` on ``Date``, ``PlainDateTime``,
+  ``ZonedDateTime``, and ``OffsetDateTime``.
 
 ## 0.10.0 (2026-04-05)
 

pysrc/whenever/__init__.pyi

@@ -175,8 +175,26 @@ class Date(_DateOrTimeMixin):
     def prev_day(self) -> Date: ...
     def nth_weekday_of_month(self, n: int, weekday: Weekday, /) -> Date: ...
     def nth_weekday(self, n: int, weekday: Weekday, /) -> Date: ...
-    def start_of(self, unit: Literal["year", "month"], /) -> Date: ...
-    def end_of(self, unit: Literal["year", "month"], /) -> Date: ...
+    def start_of(
+        self,
+        unit: Literal[
+            "year",
+            "month",
+            "week_mon",
+            "week_sun",
+        ],
+        /,
+    ) -> Date: ...
+    def end_of(
+        self,
+        unit: Literal[
+            "year",
+            "month",
+            "week_mon",
+            "week_sun",
+        ],
+        /,
+    ) -> Date: ...
     def at(self, t: Time, /) -> PlainDateTime: ...
     def to_stdlib(self) -> _date: ...
     @deprecated("Use to_stdlib() instead")
@@ -1187,12 +1205,30 @@ class _LocalTime(ABC):
     def in_leap_year(self) -> bool: ...
     def start_of(
         self,
-        unit: Literal["year", "month", "day", "hour", "minute", "second"],
+        unit: Literal[
+            "year",
+            "month",
+            "week_mon",
+            "week_sun",
+            "day",
+            "hour",
+            "minute",
+            "second",
+        ],
         /,
     ) -> Self: ...
     def end_of(
         self,
-        unit: Literal["year", "month", "day", "hour", "minute", "second"],
+        unit: Literal[
+            "year",
+            "month",
+            "week_mon",
+            "week_sun",
+            "day",
+            "hour",
+            "minute",
+            "second",
+        ],
         /,
     ) -> Self: ...
     @overload
@@ -1617,14 +1653,32 @@ class OffsetDateTime(_PyDateTimeMixin, _ExactAndLocalTime):
     ) -> Self: ...
     def start_of(
         self,
-        unit: Literal["year", "month", "day", "hour", "minute", "second"],
+        unit: Literal[
+            "year",
+            "month",
+            "week_mon",
+            "week_sun",
+            "day",
+            "hour",
+            "minute",
+            "second",
+        ],
         /,
         *,
         stale_offset_ok: bool = ...,
     ) -> Self: ...
     def end_of(
         self,
-        unit: Literal["year", "month", "day", "hour", "minute", "second"],
+        unit: Literal[
+            "year",
+            "month",
+            "week_mon",
+            "week_sun",
+            "day",
+            "hour",
+            "minute",
+            "second",
+        ],
         /,
         *,
         stale_offset_ok: bool = ...,