Date Difference Calculator
Count the exact days, weeks, and months between any two dates.
About the Date Difference Calculator
How many days until your exam? How long since you started a job? The AlarmDaddy Date Difference Calculator counts the exact time between any two dates — in days, weeks, months, and years — and optionally includes or excludes the end date.
Enter a start date and an end date. The calculator returns the total number of days between them, along with the breakdown in years, months, and days, and the count in weeks. It is handy for notice periods, project timelines, deadline counting, interest-day computations, and anniversaries. Leap years and month lengths are handled correctly.
How to use this calculator
- 1Enter the start date.
- 2Enter the end date.
- 3Choose whether to include the end day in the count.
- 4Read the total days, plus the years/months/days and weeks breakdown.
The formula
The calculator converts both dates to a day count, subtracts, and presents the total. It also derives a calendar breakdown (years, months, days) by stepping through the calendar, correctly accounting for leap years and differing month lengths.