Working Days Calculator
Counts weekdays between two dates, inclusive. Subtract any public holidays that fall on a weekday.
Result
- Weekdays (Mon–Fri)
- 22 days
- Calendar days
- 31 days
How to use the working days calculator
- Enter the start date.
- Enter the end date.
- The results update as you type, or press Calculate.
- Read the weekdays (mon–fri) first, then the supporting figures below it.
Formula
Count Monday to Friday dates in the range.
Worked example
For example, with these inputs:
- Start date: 1 Oct 2026
- End date: 31 Oct 2026
the calculator returns:
- Weekdays (Mon–Fri): 22 days
- Calendar days: 31 days
Background
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.
When sharing dates internationally, write the month as a word to avoid confusion between day-month and month-day formats.
Frequently asked questions
How does the working days calculator work?
It applies this formula: Count Monday to Friday dates in the range.
Does this count Singapore public holidays?
No. It counts calendar days or weekdays. Subtract any public holidays in the period yourself.