How it works
Parse a strict Gregorian date at UTC midnight; read the UTC weekday and count days since January 1.
Input definitions
- Calendar date
- A complete Gregorian calendar date.
A worked example
- Calendar date
- 2026-10-17
Assumptions & limits
Gregorian years 0001–9999. Historical local calendar changes are not modeled; no timezone or public-holiday inference.
Sources & review
Maintained by AnsRio. Methods and examples use automated checks; this does not imply independent professional certification.
Method updated 2026-10-17. Content checked against the stated method and examples. Our verification approach.
Common questions
Do daylight-saving changes affect calendar date results?
Date-only operations compare Gregorian calendar dates at UTC midnight. They do not count local elapsed hours. Timestamp operations require an explicit offset; individual tool assumptions state boundary rules.
How does the Day of the week for a date tool work?
Parse a strict Gregorian date at UTC midnight; read the UTC weekday and count days since January 1.
What are the assumptions and limits of Day of the week for a date?
Gregorian years 0001–9999. Historical local calendar changes are not modeled; no timezone or public-holiday inference.