Date Difference & Deadline Calculator
Calculate the difference between two dates in calendar days, weeks, and business days, or add days, weeks, or months to a start date to estimate a deadline.
Inputs
Deadline calculator
Results
- Days
- 31
- Weeks
- 4.43
- Weekdays
- 23
- Direction
- Forward
- Final date
- 2026-08-26
- Weekday
- Wednesday
How to calculate date differences and deadlines
Find the difference between two dates in calendar days, weeks, and weekdays, or add time to a start date to estimate a deadline.
How to use it
- Choose the start date and end date.
- Enable Include end date when the last day should count as part of the range.
- Review total days, weeks, and weekdays.
- Use the add-date section to add days, weeks, or months and estimate a deadline.
Weekdays
Weekdays count Monday through Friday. Public holidays are not removed because holiday calendars vary by country and region.
Inclusive ranges
Some workflows count both the first and last day. Use the include-end-date option when you need that inclusive range.
Deadline estimates
The add-date section moves a start date forward by days, weeks, or months and shows the resulting date and weekday.
Date range notes
Weekday counts include Monday through Friday only. Holidays, company calendars, and regional non-working days are not included.
FAQ
What does Include end date do?
It adds one day to the range, useful when both the start and final day should be counted.
Does it account for holidays?
No. It counts weekdays only by day of week, not by regional holiday calendars.
Can the end date be before the start date?
Yes. The tool still counts the absolute distance and labels the direction as backward.