>>>1. Proceed to do the work on week 53 of 2018 as if it were any other week
>>>2. Skip week 53 (consider it a "labor holiday" :)) and start your work on week 1 of 2019 (January 7).
>>>Guess which one they will choose? :)
>>
>>Over here, they'd start on 8th, s 7th is chrismas.
>
>I remember now. In the old country (CCCP) they celebrate, New Year, Old New Year, and everything in between :)

Why did I think that the Serbian orthodox church is the last defender of the julian calendar? Well well... So yeah, two of each. Plus the patron saint, which is an official day off, it's just that when you get hired you state which one is it for your family and you can't change your mind later. St Nikola (19th of december) is the famous day of three halves - when half the citizens have their slava, the other half are their guests, and the third half don't give a damn for religion.