What separates the strong country calendars examples from the weak

Two people agree on ten business days, start on the same date, and land three days apart. Neither made an error. One was counting against Ontario, the other against Saudi Arabia.

This page names real country calendars and shows what each one does to a deadline. A strong country calendar example states its working week, its holiday source and a version date; a weak one is an undated list of dates.

The arithmetic is yours to run; the point is which country's week you are standing in when you run it.

What to take away

The five calendars worth knowing

These five come up most often in cross-border scheduling, and each one breaks a different assumption.

Canada. Monday to Friday, with statutory holidays set federally and provincially. The federal list under the Canada Labour Code covers:

Provinces add their own. Family Day is the third Monday of February in Ontario, Alberta and British Columbia, but not in every province. Remembrance Day is on the federal list, yet Ontario and Quebec give it no statutory day off. A federal-only table will miss a provincial closure.

United States. Monday to Friday, with federal holidays published by the Office of Personnel Management. The difference from Canada is the dates, not the week. Independence Day is July 4, Thanksgiving is the fourth Thursday of November, and Martin Luther King Jr. Day is the third Monday of January.

States add their own. California observes Cesar Chavez Day on March 31, and Massachusetts and Maine observe Patriots' Day on the third Monday of April. A payment scheduled against the federal table can still land on a state office closure.

Saudi Arabia. Sunday to Thursday, with Friday and Saturday as the weekend. This is the largest single source of three-day drift against a North American count.

The holiday list follows the Hijri calendar: Eid al-Fitr, Eid al-Adha, Founding Day on February 22 and National Day on September 23. The Eid dates move about 11 days earlier each Gregorian year, so a hard-coded table goes wrong.

Israel. Sunday to Thursday for most offices, with Friday and Saturday as rest days. The holiday list follows the Hebrew calendar: Rosh Hashanah, Yom Kippur, Sukkot and Passover. Closures move each year, and some run for several days rather than single dates.

India. Monday to Friday for most corporate offices, but Saturday is a working day in many government and banking contexts. This case breaks a five-day assumption without changing the weekend, because the sixth day is partial rather than absent.

Republic Day is January 26, Independence Day is August 15, and Gandhi Jayanti is October 2. Diwali follows the Hindu calendar, so its date moves each year.

Weak calendar, strong calendar

A weak calendar is a list of dates. A strong one carries four things: the working week, the holiday list with its source and version date, the start-day convention, and the roll rule for when a deadline lands on a closure.

The substitution row is the one people skip. In Canada and the United States, a holiday falling on a Saturday or Sunday is often observed on the adjacent Monday. In a Sunday to Thursday week, the same holiday lands on a working day and needs no substitution.

Canada and the United States are the easiest of the five to pin down, because both publish fixed federal dates from a named authority each year. Saudi Arabia and Israel can be dated but not fixed, since their holiday dates move. India's partial Saturday makes any single table provisional.

Worked example: ten business days

Take a Wednesday start and add ten working days, excluding the start day.

Three countries, one phrase, three different dates. That is the problem in one line, and it is why how work calendars differ treats the working week as an input to collect rather than a constant.

Where the count itself comes from

Which days a country treats as rest days comes from law and custom, not arithmetic. The range of practice sits under workweek and weekend. The definition of a business day for a given obligation comes from the obligation, not the calendar, as set out under business day.

Canada is the clearest example of the split. The federal government publishes its holiday list, each province publishes its own, and a filing deadline set by a provincial authority follows the provincial list.

The authority that sets the deadline is the authority whose calendar applies, and that is not always the country you are sitting in.

Putting a country into a spreadsheet

Excel and Google Sheets both ship holiday tables by country, and both let you supply your own. The function names differ slightly and the argument order does not always match, which is why country calendars in Excel is worth reading before you build anything.

The two functions that matter are WORKDAY, which returns a date a given number of working days ahead, and NETWORKDAYS, which counts the working days between two dates.

Both take a holiday range as an optional argument. If you leave it out, the function uses a Monday to Friday week and no closures, which is the weak calendar in the table above.

For a Sunday to Thursday week, neither function handles it directly. The usual fix is to shift the dates by a fixed offset, run the count, and shift back.

That works, and it hides the assumption inside the offset, so write down what the offset means. A fuller treatment of the underlying arithmetic, including Leap year vs common year: which one has more working days?, is worth reading before you commit to a fixed offset for a multi-year span.

Common questions

Which country calendar should I use for a cross-border deadline?

The one belonging to the authority that sets the deadline, not the one you are sitting in. A Canadian provincial filing follows the provincial calendar even if the person preparing it is in London.

Do holiday tables in Excel and Sheets stay current?

They ship with the application and are updated on the vendor's schedule, not the country's. Check the version against the government list before relying on it for a date that matters.

Why does Saudi Arabia cause more drift than Israel?

Both run Sunday to Thursday weeks, so both drift against a Monday to Friday count. Saudi Arabia adds a Hijri holiday list whose Gregorian dates move each year, which makes a hard-coded table wrong sooner.

Can I avoid the problem by counting calendar days?

Often, yes, with a clause moving the landing date to the next day both parties work. For long intervals that is the simpler option, and the reasoning is under counting between two dates.

If you need to compare several jurisdictions side by side, Country calendars, minus the hype in 2027 lays out the differences without the guesswork.