mongodb - MongoDB 年度周是否符合 ISO 8601 标准？

Question

MongoDB manual指出 strftime 中的 $week 聚合和 %U 运算符的工作方式如下:

Returns the week of the year for a date as a number between 0 and 53.

Weeks begin on Sundays, and week 1 begins with the first Sunday of the year. Days preceding the first Sunday of the year are in week 0. This behavior is the same as the “%U” operator to the strftime standard library function.

这是否符合ISO 8601 week of the year standard ？

Answer 1

没有。 ISO 8601没有第 0 周。

根据标准:

The ISO 8601 definition for week 01 is the week with the year's first Thursday in it.

...

• If 1 January is on a Monday, Tuesday, Wednesday or Thursday, it is in week 01;
• If 1 January is on a Friday, it is part of week 53 of the previous year;
• If on a Saturday, it is part of week 52 (or 53 if the previous year was a leap year);
• If on a Sunday, it is part of week 52 of the previous year.

有一个开放的票证建议添加其他周计数选项；评论中有对 $isoweek 的建议:

https://jira.mongodb.org/browse/SERVER-7695