Day of Week Calculator
Find what day of the week any date falls on, plus the week number and days until its next occurrence.
Day of the Week
—
Day Number (1–7)
—
Week Number
—
Days Until Next
—
How It Works
Day of Week = date.getDay() (0=Sunday … 6=Saturday)
Week Number = ISO 8601 week numbering (Monday-start)
Week Number = ISO 8601 week numbering (Monday-start)
Enter any date to instantly find which day of the week it falls on. The calculator also shows the ISO week number and how many days until that same weekday occurs next (from today).
Example: July 4, 2025
Day = Friday, Day Number = 5, Week 27, Next Friday in 7 days (if today is also Friday)
Day = Friday, Day Number = 5, Week 27, Next Friday in 7 days (if today is also Friday)
Related Calculators
Last updated: 2026-08-08