This post is also available in: Deutsch

Happy New Year to all my readers!

The first challenge this year is the correct calculation of the calendar week. Because this year we have again the case that the calendar weeks differ between America and Europe.

Different calculation of the calendar week between North America and Europe

While in North America the first week of the new year is always defined as week 1, Europe follows the ISO 8601 standard. According to ISO calculation in Europe and Asia, the first week in the new year, which contains 4 or more days, is defined as week 1. In the USA and Canada, there may also be a half week as week 1.

In 2021,