Day of the week
Day of the week: use calendar date. Review the formula, worked example and calculation steps.
Inputs
Use the units shown—
Enter your values and select Calculate.
Formula & explanation
Weekday = Gregorian date’s UTC day index
Variables & units
- Calendar date
- Gregorian date
Worked example
2026-11-02 is a Monday.
Assumptions
Uses the proleptic Gregorian calendar. Historical local calendar transitions are not modelled.
Formula version 1.0.0. JavaScript floating-point arithmetic applies. Results display up to 6 decimal places; stored values retain available precision. Use the units shown.
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