Watch Calendar Correction Calculator – After Short Months
After February or a 30-day month, see whether your watch needs a date correction—and how far to advance it.
What each calendar needs
Simple dateOften assumes 31-day months. After 30-day months and February you usually advance the date by hand.
Annual calendarHandles 30- vs 31-day months. Still usually needs one correction after February.
PerpetualHandles month lengths and leap years—no monthly babysitting in normal use.
Safe habit: only quickset the date in a daytime dial window (avoid \~9 PM–3 AM on many mechanicals).
Educational model. Brand manuals win for annual/perpetual setting order and day-date wheels.
Month length cheat sheet
- 31 days: Jan, Mar, May, Jul, Aug, Oct, Dec
- 30 days: Apr, Jun, Sep, Nov
- February: 28 days, or 29 in a leap year
- Leap year: ÷4 yes, ÷100 no, ÷400 yes
Frequently Asked Questions
Why does my date show 29, 30, 31 after February? A simple date wheel often keeps advancing as if every month has 31 days.
Annual still wrong in March? Normal — annual calendars usually need a February correction.
How many clicks? Advance until the shown date matches the real civil date (tool estimates the gap).