Day of the Week Calculator
Find what day of the week any date falls on — past, present, or future.
- Free to use
- Accurate results
- No registration required
- Works on all devices
Enter any date to find out what day of the week it falls on.
Your result
Saturday
Day of the week
Day of the year255
Quarter3
AI explanation
Formula
Derived from the Gregorian calendar's day-of-week cycle for the given dateWorked example
2026-09-12
| Field | Value |
|---|---|
| Date | 12-09-2026 |
| Day of the week | Saturday |
| Day of the year | 255 |
| Quarter | 3 |
Assumptions
- Uses the proleptic Gregorian calendar for all dates, including historical dates before its adoption in various countries.
Frequently asked questions
Can I check a date far in the past or future?
Yes — enter any date and the calculator computes the day of the week using the Gregorian calendar's day-of-week cycle.
Does this account for calendar reform (e.g. the switch from Julian to Gregorian)?
No — it uses the proleptic Gregorian calendar uniformly, which is the standard approach for date calculators and matches how modern computer systems represent historical dates.
What is "day of the year"?
It's the date's position counting from January 1 as day 1 — useful for some scheduling and statistical contexts.