Date Duration Calculator
Count days between dates or add and subtract days from a starting date.
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Guide
How this date duration calculator works
This tool counts exact days between two dates or adds and subtracts a day count from a starting date.
Choose a mode
Use days between dates for durations, or add/subtract mode for deadlines and future dates.
Set date inputs
Enter calendar dates and decide whether the end date should be counted.
Review breakdowns
The tool shows total days, weeks and days, approximate months, and calendar years, months, and days.
FAQs
How do you count days between dates?
The calculator compares the two calendar dates and counts full day boundaries between them.
Should the end date be included?
Include the end date when both the start and final day should count, such as a trip with arrival and departure dates both included.
Why are calendar months different from exact days?
Calendar months have different lengths, so a month breakdown depends on the specific dates rather than a fixed number of days.
What are common uses?
Date durations help with deadlines, trips, birthdays, billing periods, project timelines, and planning windows.
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