Day of the Week Calculator

Find what day of the week any date falls on. Use this free day of the week calculator to check weekdays, weekends, day numbers, week numbers, and date details.

Calculate Day of the Week

Day of week = selected date adjusted by optional days, then converted into weekday name, day number, week number, and weekend status.
Your result will appear here.

How the day of the week calculator works

Date:
Enter the calendar date you want to check.

Optional adjustment:
You can add or subtract days before finding the weekday.

Week start:
Choose whether your week starts on Sunday or Monday for the week-position result.

Final result:
The calculator shows the weekday name, full date, day number, weekend status, and day of year.

Why use a day of the week calculator?

A day of the week calculator is useful for checking birthdays, anniversaries, appointments, deadlines, travel dates, event dates, historical dates, and schedule planning.

It helps quickly answer questions like “What day of the week was this date?” or “What weekday will this future date be?”

What your result means

Your result shows the weekday for the selected date or adjusted date. It also shows whether the date is a weekday or weekend, the day number of the week, and the day number of the year.

Day of the week calculator tips

Frequently asked questions

What is a day of the week calculator?

A day of the week calculator finds which weekday a date falls on, such as Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday.

Can this calculator check past dates?

Yes. You can enter past or future dates to find the day of the week.

Can I add or subtract days?

Yes. Use the optional date adjustment fields to add or subtract days before calculating the weekday.

Does this account for leap years?

Yes. The calculator uses calendar date math, so leap years are handled automatically.