Day of the Week Calculator
Enter any date, past or future, and find out what day of the week it was or will be — with the calendar maths explained.
November 11, 2026 is a Wednesday.
100 days later (February 19, 2027) will be a Friday.
How it works: the Gregorian calendar day-of-week is read from the date itself (JavaScript Date), and N days are added with calendar date arithmetic.
Try next: Age Calculator · Days Between Dates · Date Calculator