Day of Week from Date (Past, Present, Future)

Quick lookup: what day of the week falls on any date? Useful for scheduling, historical reference, birthday curiosity ("I was born on a Wednesday"). Supports dates 1900-2100; uses the Gregorian calendar (rejected for dates pre-1582 / 1700 / 1752 depending on country).

How to use the Day of Week from Date (Past, Present, Future)

Pick a date. The output shows the day of the week, ISO 8601 week number, day of year, and a calendar view of the month containing the date.