Fix from_date.

biscuit/apps/chronos/util.py

@@ -20,7 +20,7 @@ class CalendarWeek:
     def from_date(cls, when: date):
         """ Get the calendar week by a date object (the week this date is in). """
 
-        return cls(year=when.strftime('%Y'), week=when.strftime('%V'))
+        return cls(year=when.year, week=int(when.strftime('%V')))
 
     def __post_init__(self) -> None:
         today = date.today()