Calculating contract and leave durations
The most practical uses come from work: contracts, leave, probation periods, statutory deadlines. The golden rule is to pin down the "counting unit" the contract or regulation specifies: some periods count total days including weekends, some business days only, and some are measured in months, running to their monthly anniversary rather than a fixed number of days. That is why the tool shows every form together — total days, the breakdown (years/months/days), and business days — so you can match the text in front of you.
Example: a contract from 1 January 2026 to 8 November 2026. The distance between the two dates is 311 days, which breaks down as 10 months and 7 days, or 44 weeks and 3 days. If the contract says "the execution period is 311 days from the start date", the last day of execution is 8 November itself; but if the leave is "311 days including the first and last days", enable the include-end-day option and the occupied period becomes 312 days. The difference is a single day, but in statutory deadlines it can mean acceptance or rejection — which is why we made it an explicit option rather than a hidden assumption.
Notice and probation periods are where errors recur most. Probation under the Saudi Labour Law is capped at ninety days, extendable by written agreement, and "when does an employee's probation end?" is answered by days added to the start date, not a date guessed in months — three Gregorian months can be 89, 90 or 92 days. Reverse the calculation here: try a proposed end date, adjust until you reach the exact number, and record both dates and the days between them in the file — documentation that settles most small disputes before they start.
Official business days and Gulf weekends
There is no single definition of business days in the Gulf. Saudi Arabia and most Gulf states use a Friday–Saturday weekend for the government sector, while the UAE moved in January 2022 to a Saturday–Sunday weekend (half day Friday in government), and some authorities keep a Friday-only pattern. The tool therefore lets you choose the weekend pattern first: the same 311-day period contains a different number of business days under each pattern.
An important note: "business days" here means days not falling on the weekend only. Other official holidays — Eid al-Fitr, Eid al-Adha, national days — change yearly and are officially announced, so the tool does not subtract them; if your period includes an announced Eid holiday, subtract its days manually for the exact net.
The difference between two dates in Hijri
Calculating periods in Hijri is harder for two reasons: month lengths follow no fixed rule but are set by the Umm al-Qura table for each year (29 or 30 days), and many tools skip this and assume an average lunar month, erring by days over long periods. Our tool calculates on the table itself, day by day, so a Hijri breakdown matches what official bodies in Saudi Arabia see. You can also mix the calendars — a Hijri start, a Gregorian end — since both dates are read from the same table.
A short Hijri example to check against: from 1 Ramadan 1447 AH to 28 Jumada al-Ula 1448 AH the period is 263 days, breaking down in Hijri as 8 months and 27 days (eight whole months from 1 Ramadan to 1 Jumada al-Ula, then 27 days), and in Gregorian as 8 months and 21 days, because the Gregorian months in between are longer on average — one reason we always display both breakdowns together.
The effect of the "short month" grows with the period: five Hijri years equal, in recent examples, 1,772 days (with two leap years), while the common assumption (5 × 354 = 1,770) errs by two full days — and over the long service periods behind end-of-service benefits, two days carry a real financial effect. The practical rule: for short periods, careful manual counting suffices; for any period over a year or tied to a financial right, rely on the table day by day.