>>> n_timeunits_from_base(50, TimeUnit.SECONDS, base)
datetime.datetime(2021, 9, 10, 11, 25, 41, tzinfo=datetime.timezone(datetime.timedelta(days=-1, seconds=61200)))
+ Next month corner case -- it will try to make Feb 31, 2022 then count
+ backwards.
+ >>> base = string_to_datetime("2022/01/31 11:24:51AM-0700")[0]
+ >>> n_timeunits_from_base(1, TimeUnit.MONTHS, base)
+ datetime.datetime(2022, 2, 28, 11, 24, 51, tzinfo=datetime.timezone(datetime.timedelta(days=-1, seconds=61200)))
+
+ Last month with the same corner case
+ >>> base = string_to_datetime("2022/03/31 11:24:51AM-0700")[0]
+ >>> n_timeunits_from_base(-1, TimeUnit.MONTHS, base)
+ datetime.datetime(2022, 2, 28, 11, 24, 51, tzinfo=datetime.timezone(datetime.timedelta(days=-1, seconds=61200)))
+
"""
assert TimeUnit.is_valid(unit)
if count == 0:
new_month %= 12
year_term += 1
new_year = base.year + year_term
- return datetime.datetime(
- new_year,
- new_month,
- base.day,
- base.hour,
- base.minute,
- base.second,
- base.microsecond,
- base.tzinfo,
- )
+ day = base.day
+ while True:
+ try:
+ ret = datetime.datetime(
+ new_year,
+ new_month,
+ day,
+ base.hour,
+ base.minute,
+ base.second,
+ base.microsecond,
+ base.tzinfo,
+ )
+ break
+ except ValueError:
+ day -= 1
+ return ret
# N years from base
elif unit == TimeUnit.YEARS: