Date Difference Calculator

A date difference calculator tells you how much time separates two dates — in calendar days, weeks, completed months and years, and in business days that skip Saturdays and Sundays. Pick a start date and an end date above and every one of those counts appears instantly.

It answers the everyday questions that a calendar makes tedious: how many days are left in your notice period, how many working days a project has, how many days a fixed deposit or loan actually ran, or how long it has been since a milestone. Dates entered in the wrong order still work — the calculator uses the absolute difference.

How the difference is counted

Calendar days are the plain count between the two dates: the start date is day zero and the end date is the last day counted. So 1 January 2026 to 31 December 2026 is 364 days — one less than the 365 days in the year, because you are counting the gaps between dates, not the dates themselves. Weeks are those days divided by seven and rounded down; months and years are counted as completed calendar periods, so the same span reads as 11 completed months.

Business days count only Monday to Friday, including the start date and excluding the end date — the convention used for notice periods, SLA clocks and courier delivery estimates. Monday 17 August 2026 to Monday 24 August 2026 is 7 calendar days but only 5 business days, because the Saturday and Sunday in between are skipped and the closing Monday is not counted. Public holidays are not deducted, since they differ by state and by organisation.

How to use this calculator

• Set the start date — the first field defaults to today.
• Set the end date, such as your last working day, a due date or an anniversary.
• Read the calendar days first; use business days when the deadline is measured in working days.
• Check weeks and months for longer spans like pregnancy weeks, project phases or lease periods.
• Open the full breakdown to see weekend days and completed weeks, months and years side by side.

Indian date conventions worth knowing

A standard notice period in an Indian offer letter runs in calendar days, not working days — a 90-day notice starting 1 September ends on 30 November regardless of weekends and festivals. Statutory clocks work the same way: 30 days to file an appeal, 30 days to register a property document, and 15 days to deposit TDS after the month ends. Use the calendar-days figure for anything the law or a contract states in 'days'.

Business days matter elsewhere. Banks settle on working days, so a cheque cleared on a Friday evening may credit only on Monday, and NEFT/RTGS cut-offs follow RBI working calendars that also exclude second and fourth Saturdays. Government departments and courts count 'working days' for service-delivery promises under state Right to Service Acts. Remember that this calculator excludes weekends only — deduct gazetted holidays, Diwali and regional festivals yourself, because the list varies by state and by employer.

Frequently asked questions