Civil calendar dates only.
DateToolMage
Day of week
Show the weekday for a calendar date.
Uses civil Gregorian calendar dates (YYYY-MM-DD), not the machine clock timezone for the day count.
Method
Day counts use ordinal calendar arithmetic. Weekdays use deterministic mapping from the civil date.
Assumptions
- No holiday calendars.
- Inclusive/exclusive rules are stated in the result.
- Leap years follow Gregorian rules.
Questions
Does DST affect the result?
No. These pilots use calendar dates, not wall-clock intervals across zones.
Are bank holidays removed?
No. Holidays are not subtracted.