Overview
Find out which weekday a past or future date falls on. Useful for reviewing contracts, appointments and historical events, and for checking whether a date is a weekly weekend.
Formula
The weekday is read from the Gregorian date. Day-of-year counts days since January 1, and the week number follows ISO 8601 starting on Monday.
How it works
Pick the date
Choose the day, month and year.
Choose the weekend
To see whether the date is a weekend day.
Read the result
The weekday, day-of-year and week number appear.
Worked examples
A contract date
If a contract was signed on January 1, 2026, the tool shows Thursday.
A future appointment
Pick the meeting date to see its weekday before scheduling.
Frequently asked questions
Does it work with old dates?
Yes, within the browser-supported date range, using the Gregorian calendar.
What is the week number?
It is the week of the year under ISO 8601, where weeks start on Monday.
Does the weekend choice change the weekday?
No, it only labels the date as a working day or weekly weekend.
This calculator is for educational and informational purposes only and is not a substitute for professional advice.