Calculate Duration Between Dates
Please enter a start and end date to see the duration.
Quick Tips
- Project Planning
Ideal for calculating project runway or determining how many weeks remain until a deadline.
- Vacation Count
Calculate exactly how many days are left until your upcoming trip.
- End Date Inclusive
Standard duration calculates the difference without counting the final day. To include the end date, logically add 1 to the final days count.
- Total Conversions
Instantly converts the span into continuous formats (e.g., total absolute days or weeks).
How to Use This Tool
- 1
Select a Start Date.
- 2
Select an End Date.
- 3
Review the duration presented in mixed units and absolute totals.
The Mathematics
Duration = End Date - Start DateMeasures the span of time separating a starting point from an ending point. The output is provided in various formats (pure days, pure weeks, pure months) depending on the metric you need.
Measuring Time Precisely
Standard date duration measures the gap between two dates. However, depending on your use case, you might need to include the final day in your count.
Measures the gap *between* dates. Used for ages and time elapsed.
Counts Every day including start/end. Used for hotel bookings and shift work.
Frequently Asked Questions
Is the end date included in the calculation?
Generally, no. The calculator measures the elapsed time boundary. If you need a "days covering" count (e.g., booking a hotel start to finish), you may need to add +1 to the days.
How many days are counted in a month?
The calculation uses actual calendar logic, meaning a month duration respects if a specific month has 28, 30, or 31 days.
Can I select a start date in the future?
Yes. The calculator works identically for past-to-past, past-to-future, and future-to-future date spans.
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