A familiar situation
Prüfen Sie den Wochentag eines Geburtstags, Feiertags oder historischen Datums.
How to use this calculator
- Enter date.
- Select Calculate to see the answer and its breakdown.
- Keep a scenario, change an input and compare the results.
Use consistent units and check the assumptions below before applying the result.
How day of the week is calculated
Determine the weekday for a valid Gregorian calendar date and show its ISO weekday number. The date is validated before calculation, so impossible dates such as February 30 are rejected rather than normalized into March. 2024-02-29 was a Thursday, ISO weekday 4. The calculation validates each input and keeps its stated units explicit. It uses the proleptic Gregorian calendar; historical local calendars may differ. This is an estimate for the stated assumptions; confirm measurements and any applicable professional or local standards before relying on it.
Day of the Week Calculator is calculated from the supplied measurement fields using the units shown.2024-02-29 was a Thursday, ISO weekday 4.
Assumptions & useful context
The result depends on the values you enter and the method described above. Displayed numbers may be rounded; calculations use the unrounded values. Check that this model matches your situation before relying on it.
Frequently asked questions
Does it support dates before 1582?
It uses the proleptic Gregorian calendar; historical local calendars may differ.
What is ISO weekday numbering?
Monday is 1 and Sunday is 7.