Date & Time

Day of Week Calculator

Find which weekday a date falls on (Monday, Tuesday, etc.).

By Calculator Suite Pro Editorial Team | Last updated March 18, 2026

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Select date

Day

Monday

Date

23 March 2026

Day of Year

Week 12

Direct answer

Day of Week Calculator gives an instant result from your inputs. A day-of-week calculator tells you whether a specific date is a Monday, Tuesday, and so on. This is useful when scheduling, planning deadlines, or verifying dates in records. Formula snapshot: Day-of-year is computed as the offset from January 1 in the same year. Example: Date: 2026-02-13 -> Friday.

About this calculator

A day-of-week calculator tells you whether a specific date is a Monday, Tuesday, and so on. This is useful when scheduling, planning deadlines, or verifying dates in records.

This tool also shows the formatted date, day-of-year, and an approximate week number so you can quickly orient yourself in the calendar.

For timezone conversions (for example, a meeting time in London vs New York), use the Timezone Difference Converter instead.

How it works

A quick explanation of the logic behind the results, so you can trust what you see.

The calculator parses the selected calendar date and computes the weekday from the date value.
Because the input is a date (not a time), the result does not depend on your local time-of-day.
Day-of-year is computed as the offset from January 1 in the same year.
Week number is a quick approximation derived from day-of-year for basic planning.

Formula used

These are the core formulas and logic rules used by this calculator.

Day-of-year is computed as the offset from January 1 in the same year.
Week number is a quick approximation derived from day-of-year for basic planning.

Common use cases

Below are common real-world scenarios where this calculator is useful.

Event planning (weddings, exams, launches)
Meeting and deadline planning
Checking a birthday weekday
Verifying dates in journals or records
Work shift and rota planning
Planning trips (departure/return weekday)
Estimating week-of-year for schedules
Avoiding weekend scheduling mistakes

How to use

Pick a date using the date picker.
The weekday result updates instantly.
Use the extra stats (day of year, week number) for planning.
Change the date to compare different days quickly.

Common mistakes to avoid

These are the issues that most often cause confusing results.

Confusing a date with a datetime. Weekday is for the date only.
Typing the date in the wrong locale when entering manually.
Assuming the result changes with timezone (it shouldn’t for date-only inputs).
Using week number as an ISO week number (this tool shows a quick approximation).
Expecting a different weekday due to daylight saving time (DST affects time, not the date).

Tips and notes

Use this tool when you only care about the weekday, not the time.
For time differences between regions, use the Timezone Converter.
For counting days between two dates, use Date Difference.
For planning a schedule, check both the weekday and the date range.
If you are calculating age, the Age Calculator includes weekday-of-birth too.
For recurring weekly events, compare multiple dates across months to spot patterns.

Glossary

Quick definitions for common terms used in this calculator.

Weekday

The day name (Monday through Sunday) for a calendar date.

Day of year

The number of the day within the year (1–365/366).

Examples

Specific date

Input: Date: 2026-02-13

Output: Friday

New year check

Input: Date: 2000-01-01

Output: Saturday

Holiday planning

Input: Date: 2026-12-25

Output: Weekday shown for the selected year

FAQ

Is the weekday based on my location?

For date-only inputs, weekday is derived from the calendar date itself, not your timezone.

Can I use this for historical dates?

Yes for modern Gregorian calendar dates. For very old historical records, local calendar adoption can differ by region.

Why does the week number look different from my calendar app?

Some calendars use ISO week numbering. This tool provides a quick week-of-year approximation based on day-of-year.

Does the result change if I travel to another timezone?

Not for the same calendar date. Timezone matters when converting a specific time, not a date-only value.

Can I find out what day I was born?

Yes. Enter your birth date to see the weekday. The Age Calculator also includes weekday-of-birth.

How do I count weekdays between two dates?

Use Date Difference for the range, and combine with a calendar view if you need weekday counting across the span.

Is this calculator free to use?

Yes. This calculator is free to use without signup.

Can I use this calculator on mobile?

Yes. The calculator is mobile-friendly and works on desktop as well.

Last updated and references

Last updated: March 18, 2026

Reviewed by Calculator Suite Pro Editorial Team.

For sensitive health and finance topics, review official sources in addition to calculator outputs.

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