When do you need it?
- Deadlines and notices: “30 days’ notice” — what is the last day?
- Contracts and warranties: when a one-year warranty or six-month contract ends.
- Work: delivery in 10 working days, skipping the weekend.
- Health: a check-up in 6 weeks, or 40 days after birth.
How we calculate
- Days and weeks: added directly, so one day after 1 January is 2 January.
- Months and years: same day of the month; if that day doesn’t exist (31 January + 1 month), we use the last day of the month (28 or 29 February).
- Working days: counted one by one, skipping the weekend days you choose.
Worked examples
- 90 days from Thursday 1 October 2026 = Wednesday 30 December 2026.
- 10 working days (Friday–Saturday weekend) from Thursday 1 October 2026 = Thursday 15 October 2026, 14 calendar days.
- 3 months from 31 March = 30 June, because June has no 31st.
Days or months? The difference matters
“3 months” is not always “90 days”: from 1 October, 3 months is 1 January, but 90 days is 30 December. If a contract or notice is written in days, count days; if in months, count months. For “working days”, pick your weekly weekend: Friday–Saturday in Egypt, Saudi Arabia, Kuwait and Qatar, Saturday–Sunday in the UAE and most of the world.
Frequently Asked Questions
I want the difference between two dates instead.
Use our date difference calculator, which also counts working days.
Is the start day counted?
No. Counting starts from the next day, as in most methods, so 30 days from 1 March is 31 March.
Can I count backwards?
Yes. Choose “Before (subtract)”, for example “90 days before my trip”.
Does it skip public holidays?
No, only the weekly weekend. If the period includes an Eid or a public holiday, add those days to the result yourself.
Is the Hijri date shown exact?
It follows the Umm al-Qura calendar and can differ by a day where months start by moon sighting. For an exact Hijri date use the Hijri date converter.