Day of the Week Calculator
Find what day of the week any date falls on — past, present, or future. Get instant results with fun facts and a month calendar.
Select a Date
Select a date to discover its day
Results will appear here instantly
Click any day to select it
How to Use the Day of the Week Calculator
Find the day of the week for any date in seconds.
Choose a Date
Select a month, day, and year using the dropdown menus — or click "Today" for the current date.
See Instant Results
The day of the week appears immediately, along with the day number, position in the month, and more.
Explore the Calendar
View the full month calendar with your selected date highlighted — great for planning and context.
Origin of Day Names
The names of the days come from ancient Roman gods and celestial bodies, later adapted by Germanic and Norse traditions.
Sunday
Named after Sol, the Roman Sun god. In many cultures, it's the first day of the week and a day of rest.
Monday
Named after Luna, the Moon goddess. "Moon's day" — and statistically, the day people weigh the most.
Tuesday
Named after Mars, the god of war. For many employees, it's the most productive workday.
Wednesday
Named after Mercury (Woden in Norse). Also known as "Hump Day" — the middle of the workweek.
Thursday
Named after Jupiter (Thor in Norse). In Christian tradition, the Last Supper occurred on a Thursday.
Friday
Named after Venus (Freya in Norse). Friday the 13th is considered unlucky in some cultures, lucky in others.
Saturday
Named after Saturn, the Roman god of wealth. It's an official day of rest in Israel.
Practical Uses
Event Planning
Schedule meetings, weddings, and parties on the perfect day of the week.
Historical Research
Find what day of the week major historical events happened on.
Birthday Discovery
Find out what day you were born on, or when your next birthday falls.
Travel Planning
Check what day your travel dates fall on for better booking decisions.
Academic Scheduling
Plan exams, assignments, and academic calendars around specific weekdays.
Legal Deadlines
Calculate filing dates and contractual deadlines that fall on business days.
Days of the Week in Other Languages
| # | English | Spanish | French | Arabic | Japanese |
|---|---|---|---|---|---|
| 1 | Sunday | Domingo | Dimanche | الأحد | 日曜日 |
| 2 | Monday | Lunes | Lundi | الاثنين | 月曜日 |
| 3 | Tuesday | Martes | Mardi | الثلاثاء | 火曜日 |
| 4 | Wednesday | Miércoles | Mercredi | الأربعاء | 水曜日 |
| 5 | Thursday | Jueves | Jeudi | الخميس | 木曜日 |
| 6 | Friday | Viernes | Vendredi | الجمعة | 金曜日 |
| 7 | Saturday | Sábado | Samedi | السبت | 土曜日 |
Frequently Asked Questions
How does the Day of the Week Calculator work?
The calculator uses JavaScript's built-in Date object, which implements the Gregorian calendar algorithm, to accurately determine the day of the week for any date you enter — past, present, or future.
Can I find the day of the week for dates in the past?
Yes! You can enter any year from 1 to 9999. Find out what day of the week historical events happened, like when you were born, or when important dates occurred in history.
Does the calculator handle leap years?
Absolutely. The calculator automatically accounts for leap years, correctly showing February with 29 days when applicable and adjusting all calculations accordingly.
What is ISO 8601?
ISO 8601 is the international standard for date and time formats. It uses the format YYYY-MM-DD (e.g., 2026-03-26). According to ISO 8601, Monday is the first day of the week.
What day of the week was I born on?
Simply enter your birth date (month, day, and year) into the calculator and it will instantly tell you what day of the week you were born on, along with fun facts about that day.
Is this calculator free to use?
Yes, the Day of the Week Calculator is completely free with no sign-up required. It works on all devices — desktop, tablet, and mobile.