Bug #98347 weekday lastweek of year

• Submitted: 24 Jan 2020 17:31
• Modified: 24 Jan 2020 21:50
• Reporter: Rodrigo Benedito
• Status: Not a Bug
• Category: MySQL Server
• Severity: S2 (Serious)
• Version: 5.7.23-23
• OS: CentOS
• CPU Architecture: Any

[24 Jan 2020 17:31] Rodrigo Benedito

Description:
weekofyear('2019-12-31') return 1. This is a last week of year, is the week 53.
2019-12-29 is sunday and is in week 52, 2019-12-30 and 2019-12-31 are week 1.

How to repeat:
select weekofyear('2019-12-24');
select weekofyear('2019-12-25');
select weekofyear('2019-12-26');
select weekofyear('2019-12-27');
select weekofyear('2019-12-28');
select weekofyear('2019-12-29');
select weekofyear('2019-12-30');
select weekofyear('2019-12-31');

Suggested fix:
In change of year have a new cicle, so, don't considere last day of week in calculation or other days. In first day of year the week is 1.

[24 Jan 2020 21:50] MySQL Verification Team

Thank you for the bug report. Please check: http://week-number.net/calendar-with-week-numbers-2019.html where you could see at the bottom why 2019 has max number of week 52 and then 30/31 December is week 1.