About Day of Week
Day of Week tells you which weekday any calendar date falls on. Enter a date and it returns the day name — Monday through Sunday — which is the quickest way to check a meeting date, work out whether a deadline lands on a weekend, or settle a piece of date trivia without counting on your fingers.
The answer comes from the date's position in the weekly cycle rather than a lookup table, so it works for any date the underlying date handling supports, past or future, with no range restriction beyond what your browser can represent.
Two practical notes. The weekday is derived using your local time zone, so a date at the very edge of a zone boundary could in principle differ from what a server in another zone reports — for plain calendar dates this is rarely an issue, but it is why two tools can occasionally disagree. And the tool answers for one date at a time, so a range of dates means running it once per date or reaching for a calendar generator.
Only the name comes back. There is no numeric weekday index, no indication of whether the date falls on a weekend or a public holiday, and no ISO week number — each of those is something you would need alongside the name when building a schedule or a report. The input is a single date field with no calendar to click through, so a date has to be typed rather than picked, and there is no alternative input such as a year and day-of-year pair. Dates are also taken as written with no validation feedback beyond the resulting day name, so an out-of-range date produces an answer rather than a complaint, and the output is a fixed English name whatever the locale of the browser.
How to use Day of Week
- 1 Enter the date you want to check in YYYY-MM-DD format.
- 2 Run the tool to see the weekday name for that date.
- 3 Change the date and run it again to check a different day.
Frequently asked questions
Does it work for dates far in the past?
Yes, as far back and forward as the browser's date representation allows. The weekday is computed from the date value rather than a fixed list, so historical dates resolve correctly.
Why are the day names in English?
The output uses fixed English weekday names, which keeps the result predictable across locales. The day itself is the same everywhere; only the label would differ in another language.
Can it tell me the weekday for a whole month?
Not directly — it answers one date at a time. If you need a full month laid out with its weekdays, the Calendar Generator produces exactly that.
Does it mark weekends for me?
No, but it is easy to read off the name, since Saturday and Sunday are the weekend. The tool names the day rather than classifying it.
Free, online, and private
Free to use
Day of Week is completely free. There is no account to create, no login, and no hidden charge or usage limit.
Runs online in your browser
It is a free online tool that runs entirely in your browser. Nothing to download or install — open the page and start using it right away.
Your data stays private
All processing happens locally on your device. Your input is never uploaded, stored, or tracked, so it never leaves your browser.
How Day of Week behaves in detail
These are the specifics of this implementation — the exact ranges, defaults and fixed settings you are working with.
| Parameter | Value |
|---|---|
| Input | one date as text, default 2024-01-01 |
| Output | a single weekday name in English, chosen from a fixed seven-entry list |
| Indexing | getDay(), where 0 is Sunday and 6 is Saturday |
| Default answer | Monday — 2024-01-01 fell on a Monday |
| Units echoed | none — the weekday name is the whole result |
Compiled from the implementation of this tool and checked against it by itoolnet.
What Day of Week does not do
Knowing the edges of a tool saves more time than another list of its features. These are the cases where it will not do what you might expect.
- The weekday comes from getDay(), which reads the browser local time zone, while a date-only string such as 2024-01-01 is parsed as UTC midnight. West of UTC that instant is still the previous day, so the same input can return a different weekday on a differently configured machine.
- Nothing but the name is printed. The date is not echoed back, there is no ISO week or day-of-year alongside it, and the reverse question — which dates in a given month fall on a Tuesday — cannot be asked because there is only one input box.
- An unparseable string returns the text "Invalid date" rather than a nearest guess, and historical dates are run through the proleptic Gregorian calendar, so a date recorded before the calendar reform is judged by rules that did not apply at the time.
Tested and documented by itoolnet, the team that builds and maintains this site.