Day of Week Calculator
Enter any date — a birthday, a historical event, a future appointment — and instantly see its day of the week, day of the year and how far it is from today.
Pick a date to see its weekday.
How to use
- Pick or type any past or future date.
- Read the weekday, plus the day number in its year and the distance from today.
Weekdays are calculated from the proleptic Gregorian calendar, which is exact for all modern dates and standard for historical lookups.
Frequently Asked Questions (FAQ)
What does the day of week calculator do?
Enter any date, such as a birthday or a future appointment, and it shows the day of the week, the day number within the year, and how far the date is from today.
Which calendar does it use?
The proleptic Gregorian calendar, which is exact for all modern dates.
Can I check a birthday from years ago?
Yes. Any past or future date works, and it also tells you how far that date is from today.
What date format should I enter?
Just use the built-in date picker - no typing needed, and it accepts any valid calendar date.