Find out what day of the week any past or future date falls on.
Every calendar date corresponds to exactly one day of the week, following a predictable pattern based on the Gregorian calendar. This calculator looks that up instantly for any date, past or future.
January 1, 2000 fell on a Saturday.
It uses a calendar algorithm (accounting for leap years and the Gregorian calendar's rules) to calculate which weekday any given date falls on.
Yes, the underlying calendar math works for any valid Gregorian calendar date, though very old historical dates may use different calendar systems that this tool doesn't account for.
It's handy for confirming historical events, planning recurring events, or just satisfying curiosity about what day you were born on.