A day of the week a place does not normally work — which is not always Saturday and Sunday.
A rest day is a day of the week on which the normal working week does not run. It is a property of the WEEK, recurring and identified by day-of-week, and that is what separates it from a holiday, which is a dated occasion that happens once.
The idea is fixed in international law. ILO Convention No. 14 of 1921, and No. 106 of 1957 for commerce and offices, oblige a weekly rest of at least twenty-four consecutive hours. What neither instrument fixes is WHICH day — that is left to national law, and national law disagrees. Much of the world rests Saturday and Sunday; a large part of the Gulf and Israel rest Friday and Saturday; three Malaysian states run a school and working week from Sunday to Thursday while the rest of the country does not.
The practical consequence is that a system which hardcodes Saturday and Sunday is not slightly wrong in those places, it is wrong in both directions at once: it reports a working day as closed and a closed day as working. It will schedule a delivery into an empty warehouse on a Friday and treat Sunday as a weekend while the market is open.
| Jurisdiction | Instrument |
|---|---|
| 🌐 International | ILO Weekly Rest (Industry) Convention, 1921 (No. 14), Art. 2 Obliges a weekly rest of at least 24 consecutive hours. Does not fix which day. |
| 🌐 International | ILO Weekly Rest (Commerce and Offices) Convention, 1957 (No. 106), Art. 6 Extends the same obligation to commerce and offices. |
| Jurisdiction | Meaning |
|---|---|
| INT | The weekly rest PERIOD is fixed by convention and by most national labour codes. The DAY is not, and that is where the variation lives. |
| SA | Friday and Saturday. Sunday is an ordinary working day and the exchange trades. |
| IL | Friday and Saturday, with Friday commonly a short day. |
| MY | Saturday and Sunday nationally, but Kedah, Kelantan and Terengganu rest Friday and Saturday — a divergence inside one country. |
One week, three places, three different answers. Each of these days is a rest day in one of these countries and an ordinary working day in another — which is why a week cannot be assumed from a calendar alone.
| 🇸🇦 | Friday 8 January 2027Saudi Arabia | Rest dayA rest day in Saudi Arabia and an ordinary working day across most of Europe and the Americas. |
| 🇸🇦 | Sunday 10 January 2027Saudi Arabia | Working dayAn ordinary working day. The Saudi Exchange trades Sunday to Thursday and has no closure that week. |
| 🇮🇱 | Friday 8 January 2027Israel | Rest dayThe same Friday. The Tel Aviv Stock Exchange also trades Sunday to Thursday. |
A rest day recurs every week and is identified by day-of-week. A public holiday is a dated occasion that happens once a year.
Weekend is the colloquial name for whichever days a place rests. Rest day is the thing itself, and in much of the Gulf the weekend is Friday and Saturday.
A non-working day is the union of rest days, holidays and closures. Rest day is only the weekly part of it.
See also bank holiday · weekend · working day · non working day · public holiday · trading day · half day
We assert rest days for 2 jurisdictions of 241 — Israel and Saudi Arabia, both corroborated. For the other 239 we decline rather than assume, because a wrong week is invisible: it looks exactly like a right one. An exchange is different: its trading days are published by the exchange itself, so those are retrieved rather than assumed and we state them for all 56. See what we hold.