Day of the Week Calculator
Quick answers
| Today | October 1, 2026 | Thursday |
|---|---|---|
| Christmas 2026 | December 25, 2026 | Friday |
| New Year's Day 2027 | January 1, 2027 | Friday |
Frequently asked questions
How does the calculator find the weekday?
It uses the Gregorian calendar, which the US and UK have used since 1752. Weekdays repeat every 400 years, so any date can be calculated exactly.
What is the ISO week number?
ISO 8601 weeks start on Monday, and week 1 is the week that contains the first Thursday of the year. Some years therefore have 53 weeks.