Week number in leap year template

I have an automation that triggers Mondays and Tuesdays at 11:35, every two weeks, and I calculated that has to be on an even week.

The thing is that today (01/01/2024) the automation got triggered, and beeing the first week (even) shouldnt have been triggered.

Checking on developer tools {{ now().strftime(‘%U’) }} results in 00 instead of 01.

Why is that? Is it because this year is a leap year, and if so is there any workaround?

This is my trigger:

  trigger: 
    platform: template
    value_template: "{{ now().hour == 11 and now().strftime('%M') == '35' and now().isoweekday() in [1, 2] and now().strftime('%U') | int % 2 == 0 }}"

Thanks in advance.

That sure seems like a bug in strftime. According to their documentation:
Week number of the year (Sunday as the first day of the week) as a zero-padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.

%V is ISO Week Number and does give a 1.