🔄 Date to Week Number Converter
Find out which week of the year any date falls in — ISO 8601 approved.
What this tool helps with
ISO week number
What you can enter
- Date: 2026-04-05
Why this page is useful
Find out which week of the year any date falls in — ISO 8601 approved. This page loads fast, gives a direct answer, and then expands with useful context instead of burying the result under filler.
Frequently Asked Questions
ISO 8601 — weeks start on Monday, and week 1 contains January 4th.
Yes — it happens roughly every 5–6 years.