Day of the Week Calculator 📅

Use this weekday calculator to easily find the day of the week of any date. Calculate what day is it on a given date (what weekday is it).

Simply specify the date which you are interested in and press Calculate to see the day of the week that date corresponds to. The calculator supports any future or past date valid according to the Gregorian calendar system starting from year one AD up to year 32,767 inclusive.

The Gregorian calendar system used by the tool is common to the majority of the developed world. Countries not using the Gregorian calendar might need to resort to an alternative solution to find what day of the week is on a given date.

Day of the week calculations can be performed either according to the international standard for Representation of dates and times ISO-8601 or to the Gregorian calendar without any difference. In ISO-8601 weekdays always start on Monday and are represented as single digits, so Monday is 1, Tuesday is 2, all the way through to 7 for Sunday.

In the Gregorian calendar the names of the days of the week are derived from the names of Roman gods from the Hellenistic period. For instance, Sunday is named after the Roman Sun god "Sol" while Saturday carries the name of Saturn (Saturnus), the god of wealth and liberation, and so on. Due to the influence of the Roman culture across the ancient world, these names have spread as far as India and Japan and have since been accepted as a de-facto standard worldwide.

Since days of the week follow a strict order and are not affected by the presence of leap years, the calculation basically involves the following steps:

Assume you know that Jan 1, 2024 is a Monday and you want to know what day is Jan 18, 2024. First, calculate the number of days in between, which is 18-1 = 17. For longer periods of time, the days between dates calculator can be of immense help.

Then, divide 17 by 7 which results in 2 with a remainder of 3. Counting three whole days since Monday results in Thursday, so Jan 18, 2024 is then a Thursday. If you start with a day later in the week such as Saturday, you will need to start over if the number of days to add is larger. E.g. adding three days to a Saturday results in a Tuesday.

In much of the Americas, the U.S. included, the work week is usually defined to start on Monday while the calendar week is often considered to start on Sunday. In most of Europe both the work week and the calendar week start on Monday and end on Sunday.

As a consequence of different religious practices other parts of the world consider the week to begin with a different day of the week. Historically, many Muslim countries had their work week begin on Saturday and end on Wednesday, with Thursday and Friday being their weekend. More recently, the pressures of globalized trade and cooperation have resulted in the weekend shifting to Friday-Saturday, or even Saturday and Sunday as in the UAE.

Another country with a notably different weekend schedule is Israel where the work week begins on Sunday while Saturday is considered a sacred day.

Here is a list of countries depending on how their work week is defined and which days of the week are considered weekends.

* In those countries there are special arrangements for Fridays such as half a day off, or a prolonged lunch break to allow for religious practices.

If you'd like to cite this online calculator resource and information as provided on the page, you can use the following citation: Georgiev G.Z., "Day of the Week Calculator", [online] Available at: https://www.gigacalculator.com/calculators/weekday-calculator.php URL [Accessed Date: 01 Jul, 2024].