Day of Week Finder
What day was it — or will it be — on any date, plus the reverse: pick a weekday, get its next dates.
What day is this date?
Reverse lookup: next dates for a weekday
How to find a day of the week
- Pick a date — any date from year 1 to 9999, past or future.
- Press "Find the day." The weekday, day-of-year, and ISO week appear instantly.
- Reverse it — choose a weekday and a start date to list its next 4 dates.
- Try history — July 20, 1969 (moon landing) was a Sunday; July 4, 1776 a Thursday.
Frequently asked questions
What day of the week was October 7, 2026?
Wednesday — it is the 280th day of 2026 and falls in ISO week 41.
How do you find the day of the week for a date far in the past?
Use the proleptic Gregorian calendar: apply the Gregorian leap-year rule to every year, then count the days forward from a known anchor. This tool does it for any date from year 1 to 9999 — for example, July 4, 1776 was a Thursday and October 15, 1582 was a Friday.
How is the ISO week number calculated?
ISO weeks start on Monday, and week 1 is the week containing the year's first Thursday. Shift the date to the Thursday of its week, then count weeks from the Thursday of week 1. Because of this, early-January dates can belong to the previous ISO year — January 1, 2021 is in week 53 of 2020.
What is the day-of-year number?
The date's position in the year: January 1 is day 1 and December 31 is day 365 (or 366 in a leap year). October 7, 2026 is day 280; February 29, 2024 is day 60.
How do I find the next dates a weekday falls on?
Pick the weekday and a starting date, then count forward to the first match and add 7 days for each following one. If the start date itself is that weekday, it counts as the first result.
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Open tool →Support the codex
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