Date Difference Calculator
Calculate the exact difference between two dates in years, months, weeks, days, hours, minutes, and seconds.
Date difference
Updates as you change datesMode
What do you want to know? ?
Dates
Quick presets
Start date
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End date
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Amount to add or subtract ?
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Options
Include end date ?
Weekends ?
Public holidays ?
Display (optional)
Primary unit
Range at a glance
Every day between your two dates
Weekday
Weekend
Holiday
Today
Enter two dates to see the calendar.
Notable dates in this range
Weekdays, leap days, DST, and milestone hitsMondays
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Tuesdays
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Wednesdays
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Thursdays
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Fridays
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Saturdays
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Sundays
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Weekends
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Leap days
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Milestones
- Enter two dates to see milestones.
Examples
How It Works
The date difference calculator finds the exact time span between two dates and expresses it in multiple units simultaneously.
The include end date option adds one day to the count. This is useful when counting both the start and end dates — for example, a 3-day event from Monday to Wednesday is 2 days by subtraction but 3 days if you count both Monday and Wednesday.
Years, months, and days are calculated using calendar logic (not simple division), correctly handling months of different lengths and leap years. Total weeks, hours, minutes, and seconds use the total day count for precise conversion.
The include end date option adds one day to the count. This is useful when counting both the start and end dates — for example, a 3-day event from Monday to Wednesday is 2 days by subtraction but 3 days if you count both Monday and Wednesday.
Years, months, and days are calculated using calendar logic (not simple division), correctly handling months of different lengths and leap years. Total weeks, hours, minutes, and seconds use the total day count for precise conversion.
Tips & Best Practices
Use 'include end date' when counting both start and end days — like a hotel stay where checkout day counts.
The calculator handles dates in any order — it will show the absolute difference regardless of which date is first.
Frequently Asked Questions
When should I include the end date?
Include the end date when both the start and end days should be counted. For example: 'How many days is my vacation?' (both first and last day count). Don't include it for: 'How many days until my birthday?' (today doesn't count).
How are months calculated for the Y/M/D breakdown?
Calendar months are used, accounting for different month lengths. Going from Jan 31 to Feb 28 is 0 months and 28 days (not 1 month), because February doesn't have 31 days.