Day of the Week Calculator

Day of the Week Calculator tells you which day any date falls on, going back centuries or forward decades. It uses the browser's own calendar, which implements the proleptic Gregorian calendar, so leap years and century rules are handled correctly without a special case.

The future occurrences table answers the question behind most uses of this: when does this date next fall on a convenient day? A birthday or an anniversary advances by one weekday each year and two across a leap year, so the pattern repeats on a 28-year cycle -- visible in the table if you ask for enough years.

One caution for historical dates. Countries adopted the Gregorian calendar at different times, Britain in 1752 and Russia in 1918 among them, so a date before the local switch was recorded under the Julian calendar and the weekday people wrote down may differ from the one here.

The page shows its working, not just its answer. Where there is a formula it is printed with your own numbers substituted in, so you can check the result rather than take it on trust -- which is the difference between a calculator you can use for something that matters and one you cannot.

Everything runs inside your browser. What you type is never uploaded, never logged and never stored, and the calculator keeps working if your connection drops after the page has loaded.

• Shows day of the week, day of the year, iso week, days from today and weekend together, so you are not running it twice
• A results table you can read across
• Updates as you type, with no button to press and no page reload
• Copy the result in one click
• Free, no sign-up, and it runs entirely in your browser

The day of the week calculator is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:

• Finding what day you were born on
• Checking which weekday a future date falls on
• Seeing when a date next falls on a weekend
• Getting the day of the year and the ISO week