Timespan Calculator
What the Timespan Calculator measures
Timespan Calculator answers "how much time is between these two dates?" — pick a From date and a To date, and it shows the difference as days, business days, weeks, months, or years, depending on which mode you pick. Weeks and years are shown as a decimal (like "5.23 years") rather than rounded to a whole unit, so the result reflects the exact elapsed time rather than a rough approximation. Months and business days are counted as whole units — months as whole calendar months, business days as Monday-through-Friday days only (public holidays aren't factored in, since they vary by country).
How to use it
Pick a mode from the tabs, then set the From and To dates. All five modes share the same two date fields, so switching between "days between" and "years between" for the same date range takes one click.
Example — time between two dates
From January 1, 2020 to today is a specific number of days, roughly 5–6 years depending on the exact dates — switch to "Years between" to see that same span as a decimal like "5.61 years," or "Weeks between" to see it as roughly 293 weeks.
Calendar months vs. total days
A calendar month isn't a fixed number of days — January has 31, April has 30, February has 28 or 29. "Months between" counts whole calendar months as they actually fall (January 15 to February 15 is exactly 1 month, regardless of whether that span is 31 or 28/29 days), while "Days between" always gives the precise day count no matter which months the range crosses. Pick whichever unit actually matches what you're trying to find out.
Timespan Calculator vs. Days Calculator
These two tools answer opposite questions. Timespan Calculator takes two dates and tells you the difference between them. If you instead have one date and want to add or subtract days from it — or find what date is a given number of days from today — that's Days Calculator.
Common use cases
- Finding how many days, weeks, or months are left until a deadline or event
- Calculating project or contract duration between a start and end date
- Working out someone's tenure, membership length, or time since a milestone
- Counting business days between two dates for scheduling or SLA purposes
Frequently asked questions
Can I get the difference in weeks or months instead of days?
Yes — switch modes using the tabs to see the same date range as days, business days, weeks, months, or years.
Are weeks and years rounded?
No — they're shown as a decimal (like "5.23 years") so you get the exact elapsed time rather than a rounded approximation.
What counts as a business day?
Monday through Friday. Public holidays aren't excluded, since they vary by country and region.
Does "months between" count partial months?
No — only whole calendar months are counted; a range that's 1 month and 3 weeks shows as 1 month in that mode.