Date Calculator
Choose valid dates
0 weekdaysChoose elapsed days, inclusive dates or date arithmetic
Decide what you are counting
Use Difference to compare a start and end date. From 1 October to 2 October there is one elapsed day; counting both dates inclusively gives two calendar dates. Choose the inclusive option when your task counts each included date, rather than the gap between them.
Weekdays exclude Saturdays and Sundays. They do not remove public holidays or follow every country’s working week. For a Monday-to-Friday holiday week, a weekday total can include days when your organisation is closed. Check the calendar before treating that result as a business deadline.
Add or subtract the right units
Use Add or subtract when you know a starting date and an interval. Seven days is one week, but one calendar month can have a different number of days depending on the starting date. Check month-end and leap-year results rather than assuming a month always equals thirty days.
These are calendar-date calculations, not measurements of hours between time zones. A civil day containing a daylight-saving change need not last exactly 24 hours. For a meeting at a particular local date and time in another city, use Time Zone Converter instead.
About this tool & help
Find calendar days and weekdays, or add and subtract date units.
Your inputs stay on this device unless you deliberately share or export them.
Permissions and background limitations are explained honestly inside tools that need them.
How to use it
- Use Difference for days, weeks and weekdays between two dates.
- Use Add or subtract to move a starting date by days, weeks, months or years.
Common questions
What does inclusive mean?
Inclusive counting includes both the start date and end date.
Do weekdays exclude holidays?
Weekdays exclude Saturdays and Sundays only; public holidays vary by country and are not automatically removed.