What does this tool do?
The Day of the Week tool instantly tells you which weekday any date falls on, plus the day of the year, week number, quarter, and whether it's a leap year. It's handy for checking contract dates, planning events, or simply finding out what day you were born on.
How to use it
- Enter your values into the fields.
- The result is calculated instantly.
- Read or copy the result.
Five facts from one date
Enter a date such as 2026-12-25 and the tool shows the weekday name (Friday) in large type, alongside four extra cards: the day of the year (e.g. 359), the week number, the quarter (Q1–Q4), and whether that year is a leap year. This gives you the calendar position at a glance, not just the calendar-month number. The weekday name can be copied to your clipboard with a single tap.
Everyday uses
Use it to see what day a bill is due, a flight departs, or an anniversary lands on. History buffs can discover the weekday of any past event, including their own birthday. The week number is especially useful for people in Europe who schedule work by ISO-style week, while the quarter value is a quick reference when tracking accounting periods, fiscal reporting, or sprint planning.
Frequently asked questions
How is the week number calculated?
It uses a simple count from January 1st and treats Sunday as the start of the week. This may differ from the ISO 8601 standard, which begins weeks on Monday and defines week 1 differently.
Can I enter very old or far-future dates?
Yes. You can enter any past or future date your browser supports, and the tool calculates the weekday, quarter, and leap-year status the same way for all of them.
Is Day of the Week free?
Yes. Day of the Week and all 300+ tools on MagmaNex are completely free with no signup or account required.
Is my data safe?
Yes. Everything runs locally in your browser. The data you enter is never sent to a server, stored, or shared.
Does it work on mobile?
Yes. Day of the Week works on phones, tablets and desktops — no app download needed.
🔒 Privacy: everything runs in your browser, your data is never sent to a server.