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What Day of the Week Was (or Will Be) a Date?

Enter any date — past or future — to see exactly which day of the week it falls on, plus its day of year and ISO week.

How do you find the day of the week for a date?

Enter the date below and Calcadian returns its weekday instantly using Gregorian calendar rules, including leap years. It works for birthdays, historical dates, deadlines, and dates decades into the future.

Weekdays are calculated from the calendar date in UTC, so the result does not shift with your time zone.

Result

Day of week
Saturday
Date
Saturday, August 15, 2026
Day of year
227 of 365
ISO week
Week 33 of 2026

Saturday, August 15, 2026 fell on a Saturday. That is today.

How to find the day of the week for any date

  1. Enter the date you want to check.
  2. Read the day of week from the result card.
  3. Check the day of year to see how far into the year that date sits.
  4. Use the ISO week if you plan in weekly sprints or payroll periods.

Examples

  • July 4, 1976 was a Sunday.
  • January 1, 2000 was a Saturday.
  • December 25, 2030 falls on a Wednesday.

Why the weekday matters

Weekdays decide whether a deadline lands on a working day, whether a contract term ends on a weekend, and how a delivery or payment date shifts. If you need to count only working days instead, use the Business Days Calculator.

Related tools

Week Number CalculatorFind the ISO week number for any date.Open Date Difference CalculatorCount days, weeks, months, and years between two dates.Open Add or Subtract Days CalculatorFind a future or past date by adding or subtracting time.Open Days Until CalculatorCount how many days are left until any future date.Open Business Days CalculatorCount working days between two dates, excluding weekends.Open

Frequently asked questions

What day of the week was I born?
Enter your date of birth above. The calculator returns the exact weekday for any date, including dates far in the past.
How far back and forward does this work?
It works for any date your browser can represent, covering roughly the years 1 to 275760 in the proleptic Gregorian calendar.
Does it account for leap years?
Yes. Weekday calculations use the full Gregorian calendar rules, including leap years and century exceptions such as 1900 (not a leap year) and 2000 (a leap year).
Is the weekday the same everywhere in the world?
Calcadian computes the weekday from the calendar date in UTC, so it does not shift with your local time zone. A specific moment in time can fall on different weekdays in different time zones, but a calendar date always has one weekday.
What is the difference between this and the week number calculator?
This tool tells you the weekday name (Monday to Sunday). The week number calculator tells you which ISO week of the year the date falls in.
Can I use it for historical dates before 1582?
The result uses the proleptic Gregorian calendar, projecting today's rules backwards. Historical records from before the Gregorian reform may use the Julian calendar and can differ by several days.

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Calcadian calculators are for general planning and informational use. Please verify critical deadlines, legal, payroll, tax, HR, or official requirements with the relevant authorities or a qualified professional.