Date Difference Calculator
Find out exactly how much time lies between two dates, or jump forwards and backwards from a date. Enter a start and end date to see the gap in years, months and days, plus the total days, total weeks and business days (Monday to Friday). Switch to the add/subtract tab to work out a deadline or due date, complete with its weekday. Everything runs in your browser, with an optional Thai Buddhist Era display and nothing sent to a server.
Adds one day so both the start and end dates are counted (e.g. a hotel stay or leave request).
Displays result dates using the Buddhist Era (year + 543).
Your results will appear here
Pick two dates to count the days between them, or add and subtract from a date.
Duration
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Total days The whole span expressed as a single number of days.
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Total weeks Total days divided by 7, rounded to two decimals.
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Business days Weekdays only (Monday to Friday), excluding Saturday and Sunday. Public holidays are not counted.
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Result date
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Day of week Which day of the week the result date falls on.
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Days from start How many calendar days the result is from the start date.
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ISO date The result in YYYY-MM-DD format for spreadsheets and forms.
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How to use
- Open the Difference tab and choose a start date and an end date.
- Read the duration in years, months and days, plus total days, weeks and business days.
- Tick "Include the end day" when both the first and last day should be counted.
- Switch to the Add / subtract tab, pick a start date, then add or subtract a number of days, weeks, months or years.
- Turn on "Show Thai Buddhist year" for B.E. dates, then Copy summary to reuse the result.
Features
- Difference between two dates in years, months and days
- Total days, total weeks and business days (excludes weekends)
- Optional "include the end day" toggle for inclusive counting
- Add or subtract days, weeks, months or years from any date
- Shows the weekday and ISO (YYYY-MM-DD) date of the result
- Thai Buddhist Era (B.E.) display and 100% in-browser privacy