Day of the Week Finder
Find what day of the week any date falls on, plus its day and week number of the year.
Figuring out what day of the week a past or future date fell or falls on — confirming that a historical event happened on a Tuesday, or checking whether a future deadline lands on a weekend — isn't something most people can calculate reliably in their head beyond a few weeks out, since it depends on an irregular pattern of month lengths and leap years.
This tool instantly finds the day of the week for any date, along with two related figures: the day's position within the year (1-366) and its ISO-style week number, both useful for scheduling, payroll, and reporting contexts that reference "week 23" or "day 145" rather than a calendar date.
How to use Day of the Week Finder
- 1
Enter a date
Select any past or future date using the date picker.
- 2
Read the results
See the day of the week, day of the year, week of the year, and whether it's a leap year.
Features
- Works for any past or future date
- Shows day of year and week of year alongside day of week
- Flags whether the selected year is a leap year
- Instant live calculation
Frequently asked questions
Common mistakes to avoid
- Assuming a date pattern (like 'the 13th is always a certain weekday') holds across multiple months — weekday patterns shift due to varying month lengths.
- Confusing week-of-year numbering conventions — different standards (ISO 8601 vs. US convention) can number weeks slightly differently near year boundaries.
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