Time & Date Tools
Week Number Calculator
Calculate ISO week number and get detailed week information for any date
Pick a date
Week boundaries follow ISO week (Monday–Sunday). Week number and ISO week-year come from your selection.
ISO week
Week number
42
ISO week-year
2026
Working days
5
Weekend days
2
Range
Monday, October 12, 2026
through
Sunday, October 18, 2026
Days in week
Monday, October 12, 2026
Tuesday, October 13, 2026
Wednesday, October 14, 2026
Thursday, October 15, 2026
Friday, October 16, 2026
Saturday, October 17, 2026
Sunday, October 18, 2026
Full report
Week Number Calculation Results: Week 42, 2026 Week Range: First Day: Monday, October 12, 2026 Last Day: Sunday, October 18, 2026 Days in Week: Monday, October 12, 2026 Tuesday, October 13, 2026 Wednesday, October 14, 2026 Thursday, October 15, 2026 Friday, October 16, 2026 Saturday, October 17, 2026 Sunday, October 18, 2026 Summary: Total Days: 7 Working Days: 5 Weekend Days: 2