Choose any date to see which day of the week it falls on, plus useful calendar details.
The calculation uses the actual Gregorian calendar date and works for past and future dates supported by your browser.
A calendar date maps to one of seven weekdays. This calculator performs that calendar conversion directly, so you do not need to count backward or forward from a known date.
The day-of-year count starts at 1 on January 1. The ISO week number follows ISO 8601, where weeks begin on Monday and week 1 contains January 4.
Yes. The selected date is evaluated against the actual calendar, including February 29 in leap years.
January 1 is day 1. December 31 is day 365 in a normal year and day 366 in a leap year.
Yes. ISO week numbering can place early-January or late-December dates in a neighboring ISO week-year.