I understand the bull week, the last week where you get pay before Christmas, also bull month for monthly paid, I remember the efforts to get as much over time in as one could until that point, after which people went the reverse and tried to take any loo days owed before losing them if not taken by new year. For management it could become a problem where people would just announce I'll be taking holidays from tomorrow or I will lose them. Some firms would allow holidays to be taken in the first few months of new year.
This could mean people would wait until last few days before Christmas before shopping in the UK. In USA the tax year may be different to UK so there may be a push to get money in before Christmas, but 5th of April is UK tax year so there is no Black Friday in the UK.
