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Workflows
Coding workflows · Clamped calendar month shifts
03
A concrete starting point
Shift a date by whole calendar months and clamp its day to the target month's final day. Check January 31 in leap and non-leap years plus a negative shift, rejecting fractional offsets and years outside the supported range.
Define the change
Describe the input, expected output and boundaries that must stay intact.
Inspect the work
Review the proposed edits and any commands before relying on their result.
Check the outcome
Compare actual behavior with the expected result. If a check fails, investigate it before applying more changes.
Clamped calendar month shifts
A concrete starting point
from calendar import monthrange
from datetime import date
def add_months(day, delta):
if type(day) is not date or type(delta) is not int:
raise ValueError("month.input")
year, month0 = divmod(day.year * 12 + day.month - 1 + delta, 12)
if not 1 <= year <= 9999:
raise ValueError("month.year")
last = monthrange(year, month0 + 1)[1]
return date(year, month0 + 1, min(day.day, last))The example is a starting point for a real project, not a claim that generated code is already tested. Adjust paths, dependencies and expected behavior to match your application.
