# ISO 8601 ![rw-book-cover](https://readwise-assets.s3.amazonaws.com/media/uploaded_book_covers/profile_519944/MontreGousset001.jpg) ## About - Author: wikipedia.org - Title: ISO 8601 - Tags: #articles - URL: https://en.wikipedia.org/wiki/ISO_8601 ## Highlights As a consequence, if 1 January is on a Monday, Tuesday, Wednesday or Thursday, it is in week 01. If 1 January is on a Friday, Saturday or Sunday, it is in week 52 or 53 of the previous year (there is no week 00). 28 December is always in the last week of its year. The week number can be described by counting the Thursdays: week 12 contains the 12th Thursday of the year. - Note: Easy way to remember what week we are in. I should use this for defining the quarters for my finances ---