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Clear, practical guides on week numbers, the ISO 8601 standard, pregnancy weeks and the calendar tools we build.

11 articles · Page 2 of 2

Week Numbers 6 min read

How many weeks are in a year? (2025 and 2026 explained)

How many weeks are in a year? Every calendar year has 52 weeks plus 1 or 2 extra days, but in ISO 8601 some years, like…

May 31, 2026 Read →

ISO 8601 8 min read

ISO 8601 week numbers run Monday to Sunday, so the start of January can fall in week 52 or 53 of the year before. Here'…

May 31, 2026 Read →