About the Date Difference Calculator
How long between two dates is a surprisingly fiddly calculation because months and years vary in length. This tool does it properly: enter a start date in the pane and an end date in the toolbar (or leave it as "now"), and it reports the difference broken into years, months and days, and also as total days, weeks, hours, minutes and seconds. It even counts business days, Monday to Friday, between the two.
It is useful for working out an age, a project duration, days until a deadline, or the gap between two events. Dates can be in almost any format or Unix timestamps. For an age specifically, the Age Calculator adds the next-birthday countdown; to add or subtract a period from a date, the Add or Subtract Time tool.
How to use
- Enter the start date in the pane.
- Enter the end date in the toolbar, or leave it as "now".
- Read the breakdown and totals.
Common questions
- How are years and months counted?
- Calendar-aware: from 5 Jan to 5 Mar is two months exactly, accounting for different month lengths.
- What are business days?
- Weekdays (Monday to Friday) between the two dates. Public holidays are not excluded.
- Can the end date be before the start?
- Yes; the difference is shown with a note that the end is earlier.