What is the Date Difference Calculator?
The date difference calculator counts the time between two dates in every useful unit: days, weeks, months and years, plus business days (Monday to Friday) and weekend days.
It is handy for notice periods, contract lengths, leave applications, project deadlines, rent periods and visa stays. Tick "Include end date" when both the start and end days should count, as in most leave and hotel calculations. To add days to a date instead, use the Date Calculator (Add or Subtract Days).
How to use the Date Difference Calculator
- Choose the start date.
- Choose the end date.
- Tick Include end date if the last day should be counted.
- Read the total days and the breakdown in weeks, months, business days and hours.
Formula
Days = end date − start date (+1 if the end date is included)
Example
From 1 January 2026 to 31 March 2026 is 89 days, or 90 days if you include the end date. That is 12 weeks and 5 days, with 64 business days.
Business days vs calendar days
Calendar days count every day. Business days skip Saturdays and Sundays. Public holidays are not removed automatically, so subtract them yourself using the Pakistan Public Holidays list if needed.
Common uses
- Notice periods and probation periods
- Days left until an exam, wedding or trip
- Number of nights for a hotel booking
- Loan, rent or subscription periods
- Pregnancy and medical follow-up dates
You may also need
People who use the Date Difference Calculator often need these related tools too:
- Date & Time Difference: Get the exact time between two date-times, each in its own time zone, in days, hours, minutes and seconds.
- Islamic Date Today (Hijri Converter): Today's Islamic (Hijri) date and a two-way converter between Hijri and Gregorian dates, with the Islamic month names.
Frequently asked questions
How many days are there between two dates?
Pick both dates and the calculator shows the exact number of days, and the same period in weeks, months and years.
Does the calculator include the end date?
By default no. Tick "Include end date" to add one day, as many leave and contract calculations require.
How are business days counted?
Monday to Friday are counted; Saturdays and Sundays are skipped. Public holidays are not removed.
Can the end date be earlier than the start date?
Yes. The calculator swaps them and shows the difference.
How many weeks are between two dates?
The result shows full weeks and leftover days, for example 12 weeks and 5 days.
Is the Date Difference Calculator free to use?
Yes. The Date Difference Calculator on Custom Converter is completely free, with no sign-up, no daily limit and no watermark.
Does the Date Difference Calculator work on mobile phones?
Yes. It is built mobile-first and works on Android phones, iPhones, tablets and computers in any modern browser, with no app to install.