Day of the week calculator
Choose a date and see which day of the week it falls on, with its day number in the year, its ISO week and its quarter.
How to use it
- Pick a date in the "Day of the week" box. It starts on today's date, and the "Today" button brings that date back.
- Type your birth date to find out what day you were born, or a future date such as a wedding, a deadline or a trip.
- Read the weekday at the top of the results, then the "Day of the year", "ISO week number" and "Quarter".
- Check "Days in the month", "Leap year" and "Days left in the year" further down. The results update as soon as you change the date.
Good to know
A weekday lookup answers more questions than you might expect: the day you were born, the day of a wedding or anniversary, whether a deadline lands on a weekend, or the day a past event took place. Along with the weekday, the tool shows how far into the year the date falls and how many days are left.
The ISO week number follows the ISO system, in which weeks start on Monday and week 1 is the week with the year's first Thursday. Calendars that start weeks on Sunday can show a different number, so match the system your school or employer uses. The quarter splits the year into four blocks of three months.
Need the number of days between two dates, or the date 90 days from now? The full Date Calculator, with tabs for "Days between dates" and "Add or subtract", is one click away in the breadcrumb.
Questions and answers
How do I find out what day I was born?
Enter your date of birth in the date box on the "Day of the week" tab. The weekday appears at the top of the results straight away.
What does the ISO week number mean?
It numbers the weeks of the year under the ISO system, where weeks start on Monday and week 1 contains the first Thursday of the year.
How can I tell if a year is a leap year?
The "Leap year" line answers Yes or No for the year of the date you chose, and "Days in the month" shows 29 days for a February in a leap year.
How many days are left in the year?
The "Days left in the year" line counts the days after the chosen date, up to and including 31 December.
Can I check a date far in the past?
Yes, but every date is worked out with today's Gregorian calendar rules. For dates from before your country adopted that calendar, records from the time may name a different weekday.