I've always found that funny, Celebrating freeing the slaves after enslaving them in the first place. I don't know where, but there's something tricky about that. Don't you think?
Nah. All the Brit's who wished they had Thanksgiving moved and started Canada. They were so excited about it they couldn't wait and decided to have it a month early.
No, we don't wish for our own version of a "Thanksgiving Day", as it would not mean anything, but the UK has several "Bank" or public, Holidays each year.
It's hard to define a British holiday season now. Even many sea-side resorts tend now to have nearly year-long seasons, with a low point in January and February, the coldest time of year. The "off-season" visitors don't go for the beach and swimming, but simply for a relaxing break from home, and to visit those tourist attractions open all year round, albeit many on reduced hours. (I know 'cos I live in a seaside resort!)
The main English school holiday is a0 5-6 week break between the end of one School Year and the beginning of the next, straddling August, which also has its last Monday as August Bank Holiday. Being in the height of Summer, the combination means most families take their main holiday week or more often now, fortnight, in this time; either staying in the UK or going abroad.
One drawback is that the various ferry companies operating between Britain, Eire and the continent of Europe, hike their fares for the Summer season well above those for the quieter times of year.
In the late 19C and for much of the 20C many companies closed for an annual, set week in Summer; but with the steady rise in leave allowances, flexible working hours etc, improvements in employment conditions generally, and large-scale changes in working methods, the practice is now all but dead, apart more recently, from Christmas - New Year.
Christmas' Twelve Days count from Christmas Day, but many companies close for about a week from Christmas to New Year's Day. Depending on how these fall in the calendar, many employees take the full week anyway, so it's more economical to close the whole firm rather than light and heat all the building for a much-depleted staff - everyone just has to work harder to complete the orders on time, on their return! Obviously many organisations have to keep working but work out suitable rotas. The ones who lose most are shop staff because the wretched supermarkets insist on opening 7 days a week and for whole days even without considering the January Sales - though have to close by 4pm on Sundays. This is relatively recent, and is driven purely by commercial interest; not so long ago most British shops, like most businesses, closed on Sundays - a religious relic but nonetheless valuable for giving their employees the same day off as most other people enjoyed!
Christmas Day, Boxing Day and New Year's Day are Bank Holidays, transferred to the week-day if they fall on Saturday or Sunday. Good Friday and Easter Monday, May-Day and Whit Monday (the Mondays bracketing May) are also public holidays. All bar New Year's Day and May Day are religious festivals, giving you the derivation of the word "holiday". May Day was introduced by a Labour Government in the 1970s (ISTR) as it seemed suitably socialist (think USSR); but few people bothered even then with its political theme.
Incidentally, Hallowe'en was a religious festival too, until high-jacked by naked commerce with all its invented pumpkins and witches nonsense. It never became a holiday though. Nor did November the Fifth, which commemorates the foiling of what nowadays would rightly be called a "terrorist attack"; although the effigy-burning is odd as the original Guido Fawkes and his co-conspirators were hanged, drawn and quartered, not burnt at the stake.