Date to Weekday
Enter any calendar date and instantly see which day of the week it falls on. This tool supports years from 1 to 9999 and gives you extra details like the ISO week number and the day of the year.
Day of the Week for Any Date
The displayed date format is determined by your browser and regional settings (for example DD.MM.YYYY or MM/DD/YYYY).
Quick Date Facts
Today
Weekday Highlights for This Year
All values are calculated based on today’s date in your local time zone and the current calendar year.
How this date to weekday calculator works
This tool shows you the exact day of the week for any valid calendar date. You simply select a date and the calculator uses a precise algorithm to determine whether it falls on a Monday, Tuesday, Wednesday, Thursday, Friday, Saturday or Sunday.
It works for modern dates as well as very old or future dates, because the internal calculation is based on a continuous proleptic Gregorian calendar. As long as your browser supports the year, the tool can tell you the weekday.
The displayed date format is determined by your browser and regional settings (for example DD.MM.YYYY or MM/DD/YYYY). The weekday result is calculated from the selected calendar date itself and does not depend on how the date appears on screen.
Examples of what you can use it for
- Planning events: What day of the week will a future birthday, meeting or deadline fall on?
- Looking up past dates: What day of the week did an important memory or a historical event take place?
- Scheduling work: Is a specific date a weekday or part of the weekend?
- School and exams: Which weekday do exam dates, holidays, or semester start and end dates fall on?
- Curiosity: What day of the week was I born on, or which weekday is Christmas Eve this year?
Related Calculators
If you’re working with calendar dates, you might also want to measure a full date range with the Days Between Dates Calculator, add or subtract time from a date using the Add or Subtract Date Calculator, or check the ISO calendar week for a date with the Week Number Calculator. If you want to calculate time spans between clock times, the Time Duration Calculator is a useful companion.
These tools are often combined for planning, scheduling, and understanding timelines across dates, weeks, and time ranges.
- How many days are between two deadlines?
- How long did a trip last from departure date to return date?
- Count days across a project start and finish date.
- What date will it be 45 days from today?
- What date was 2 months before a specific day?
- Calculate a follow-up date for an appointment.
- Which ISO week does a date fall into?
- What is the current ISO week number?
- Find the week number for planning and reporting.
- How long is a meeting from start time to end time?
- Calculate shift length when work crosses midnight.
FAQ
Which years are supported?
The calculator is designed to work with a very wide range of years, from year 1 up to year 9999, depending on what your browser allows for the date input. There is no artificial minimum such as “from 1900 only”.
Why do I see a different date format?
The date picker uses your browser’s regional settings. In some countries the format is day–month–year, in others month–day–year. The internal weekday calculation is always correct, no matter how the date looks on screen.
What additional information do I get?
Besides the weekday, the tool shows the ISO week number and the day of the year. This gives you a quick calendar overview without having to open a separate calendar app.
Can I use this for historical research?
For modern dates the result is fully reliable. For very old dates, the tool assumes the proleptic Gregorian calendar, which extends the modern Gregorian rules into the past. Historical sources may have used other calendar systems, so results can differ for very old years.
Do time zones or daylight saving time matter?
No. The weekday calculation is based purely on calendar days and is independent of time zones or daylight saving time, so the weekday result is the same everywhere.