Day of the Week Calculator
Tells you which weekday any date falls on.
Result
- Day
- Monday
How to use the day of the week calculator
- Enter the date.
- The results update as you type, or press Calculate.
- Read the day first, then the supporting figures below it.
Formula
Based on the Gregorian calendar.
Worked example
For example, with these inputs:
- Date: 9 Aug 1965
the calculator returns:
- Day: Monday
Background
Age is calculated in completed years, months and days. Someone born on 29 February is usually treated as turning a year older on 28 February or 1 March in non-leap years, depending on the rule being applied.
The Gregorian calendar has months of 28 to 31 days and adds a leap day almost every four years, which makes counting days by hand surprisingly error-prone. Converting dates to day numbers and subtracting avoids the problem.
Frequently asked questions
How does the day of the week calculator work?
It applies this formula: Based on the Gregorian calendar.
Does this count Singapore public holidays?
No. It counts calendar days or weekdays. Subtract any public holidays in the period yourself.