What is Day of Week Calculator?
A day of week calculator finds what day of the week any date falls on — past, present, or future. It also shows the day of year (1-366), ISO week number, quarter, whether it's a leap year, and other calendar facts about the date.
How to Find the Day of the Week for Any Date
Discover which day of the week any historical or future date falls on.
- Enter a date: Type or select any date — past, present, or future.
- View the day of the week: See which day (Monday through Sunday) the date falls on.
- Explore calendar details: View additional info: day of year, ISO week number, quarter, and whether it's a leap year.
Frequently Asked Questions
What day of the week was I born?
Enter your date of birth in the Day of Week Finder and it instantly tells you which day of the week you were born on (Monday, Tuesday, Wednesday, etc.).
What day of the week is January 1, 2026?
Enter January 1, 2026 in the calculator and it shows the day of the week along with the day of year, ISO week number, and quarter.
How do I find out what day a date falls on?
Enter any date in our Day of Week Finder. It works for historical dates (e.g., what day was July 4, 1776?) and future dates (e.g., what day is December 25, 2030?).
What is the ISO week number for a date?
Our calculator shows the ISO 8601 week number for any date. ISO weeks start on Monday, and week 1 is the week containing the first Thursday of the year.
How do I check if a year is a leap year?
Enter any date in that year and the calculator shows whether it's a leap year. Leap years are divisible by 4, except century years must be divisible by 400.
What quarter of the year does a date fall in?
Our calculator shows the quarter (Q1-Q4) for any date: Q1 = Jan-Mar, Q2 = Apr-Jun, Q3 = Jul-Sep, Q4 = Oct-Dec.