What is a Date Difference Calculator?
Project timelines, notice periods, interest windows, visa stays, all come down to “how many days between these dates”, and often specifically working days.
Pick two dates for calendar days, Monday-Friday weekdays, and full weeks. Counts are exclusive of the end date, the convention most contracts use.
Which of the three counts you want depends on the clause. Interest and rent run on calendar days, delivery and notice commitments usually on weekdays, sprints and schedules on full weeks. One trick the exclusive end date makes easy: pick the first of a month and the first of the next, and the weekday figure is that month’s working days exactly, with no off-by-one to argue about.
Frequently asked questions
How do I count a 30-day notice period?
The usual convention is that the day of service does not count and the period ends at the close of the thirtieth day after it, so notice served on 1 April runs out on 1 May. Conventions do vary between contracts, so count it here and then confirm the wording in writing.
How many working days are in a month?
Between 20 and 23, depending on where the weekends fall: a 31-day month starting on a Monday has 23, and a 28-day February always has exactly 20. Public holidays come off that figure, and this tool does not subtract them.
Is the end date included?
No. Monday to Friday counts 4 days. Add 1 if your context counts both endpoints.
Are public holidays excluded from weekdays?
No: holidays vary by country and state; subtract yours from the weekday count.
Can dates be in reverse order?
Yes: the difference is shown as a positive count either way.
Does it handle month/leap-year boundaries?
Yes: real calendar arithmetic throughout.