Wrong week number when first day of week is Sunday

[martakostova]

Hello there,

one of our clients reported wrong week number. The interesting part is that when first day of week is Monday, everything is as it should be, but when the first day of week is Sunday, it shows that first week for 2022 is 9th-15th of January, instead of 2nd-8th.
This happens on latest 0.6.8 version.

Please help!

[martakostova]

After finding the same problem in stackoverflow I made a PR with the fix.
I hope this helps somebody :)