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Day of the Week Calculator

Discover the day of the week for any date effortlessly with our Day of the Week Calculator. Accurate and intuitive, plan your events and appointments with precision. Your go-to tool for date-related scheduling.

Day of the Week Calculator

A Day of the Week Calculator, also known as a Day Calculator or Day Finder, is a tool or a system that can determine the day of the week for any given date. It can take a specific date (typically in the format of month, day, and year) as input and calculate which day of the week it falls on.

This calculation is based on the Gregorian calendar, which is the most widely used calendar system in the world. The Gregorian calendar has a repeating cycle of seven days in a week, and a Day of the Week Calculator uses mathematical algorithms or formulas to perform these calculations. One common algorithm used for this purpose is the Zeller's Congruence formula, which can determine the day of the week for a given date.

How Does it Work?

Calculate the Day of the Week Using Zeller's Congruence.

  • h = (q + 13(m + 1) / 5 + K + K/4 + J/4 - 2J) % 7
  • h is the day of the week (0 = Saturday, 1 = Sunday, 2 = Monday, ..., 6 = Friday)
  • q is the day of the month (16)
  • m is the adjusted month (10)
  • K is the year of the century (year % 100)
  • J is the zero-based century (year / 100)

Plug in the Values, For Example.

  • q = 16
  • m = 10
  • K = 23 (since 2023 % 100 = 23)
  • J = 20 (since 2023 / 100 = 20)

Calculate the Result.

  • h = (16 + 13(10 + 1) / 5 + 23 + 23/4 + 20/4 - 2*20) % 7
  • h = (16 + 143/5 + 23 + 5.75 + 5 - 40) % 7
  • h = (16 + 28.6 - 40) % 7
  • h = 4.6 % 7
  • h = 4 (after rounding)

Maunal - How to Use the Day of the Week Calculator

  • Enter the Date

Enter any date about which you want to know the informations. For example - Day (i.e. 16), Month (10 for October) Year (2023) from dropdown menu.

  • Calculate

After entering the date, click the "Calculate" button for gaining further informations.

  • Result

Day of the Week

It provides the specific day of the week for the given date, which helps users identify what day falls on that date.

Day Count

It informs you about the day count within the year, indicating how many days have passed and how many days are remaining until the end of the year.

Day of the Week Count

This feature tells you the count of the specific day of the week (e.g. Monday) within the year, including how many of those days have already occurred and how many are yet to come.

Benefits of the Day of the Week Calculator


You can quickly figure out which day of the week a future date will be, making it easier to plan events, appointments, and special occasions like birthdays or vacations.


If you need to schedule tasks or activities, knowing the day of the week helps you pick the most convenient or suitable days.

Historical Dates

You can use it to find out what day of the week important historical events or personal milestones happened on.


A day of the week calculator can help you organize your time and tasks effectively, allowing you to allocate your time and resources wisely.

Avoid Mistakes

It prevents you from making scheduling errors and ensures you don't miss important dates or deadlines.

Time Management

By knowing the day of the week, you can better manage your time, helping you stay on top of your commitments and responsibilities.

Travel Planning

If you're planning a trip, it can assist in choosing the most convenient days for your journey.


You can use it to set weekly goals and track your progress by associating tasks with specific days.

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