Apr 29, 2026
- ISO weekday
- 3
- Sunday-based index
- 3
- Date
- 2026-04-29
Day of the Week Calculator
Use this free day of the week calculator to find whether a date falls on Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday.
Research-backed assumptions Formula steps Examples included Private in-browser use
Formula steps
- Read the entered date as a calendar date.
- Use UTC date math so daylight-saving time does not shift the date.
- Return both the weekday name and ISO weekday number.
How to use the day of the week calculator
- Choose a calendar date.
- Press Find day of week to see the weekday name and ISO weekday number.
- Use Date Calculator instead when you need days between dates.
- Check time zones separately for events that happen near midnight.
Common uses
Find the weekday for a birthday, deadline, holiday, or event date.
Check ISO weekday numbers for scheduling notes.
Compare leap-day and future date examples.
Use date-only math without time-of-day confusion.
Examples
Wednesday
Friday
Thursday
Frequently asked questions
Plain-language answers about when to use the tool, what it does with your inputs, what to double-check, and how privacy works.
When should I use the Day of the Week Calculator?
Use it when your task matches one of these common needs: Find the weekday for a birthday, deadline, holiday, or event date. Check ISO weekday numbers for scheduling notes. It works best when you already know the values, dates, units, or settings the page asks for.
What is the Day of the Week Calculator doing with my inputs?
In plain language: The calculator reads the date as a UTC calendar date and returns the weekday name, Sunday-based index, and ISO weekday number. The examples on the page are there so you can compare your inputs with a filled-out calculation before copying the answer.
What should I double-check before trusting the answer?
This uses calendar-date math only. Historical calendars, local calendar reforms, and time-zone-specific date changes can require specialized references. Also check that you used the right unit, date, scale, or mode because small input changes can change the result.
Does the site save what I enter?
No. The calculator runs in your browser tab. Your recent answers stay only on the page while you use it, and they are not sent to a server.