Day of the Week Calculator
Find the weekday, day of year, and week number for any date.
How it works
Choose any date to see which weekday it falls on. The ISO week number follows the international standard in which weeks start on Monday and week 1 contains the first Thursday of the year. Useful for planning, birthdays, and project schedules.
FAQ
Is this calculator free?
Yes. No signup is needed and nothing you enter is stored.
Is the result exact?
Results are rounded for display. For financial, medical, or legal decisions, confirm with a professional.
Do my numbers leave my device?
No. The calculation runs in your browser.