Bank holidays was the old fashioned term coming from the fact that it was originally the time when the financial institutions including banks were granted holidays.
Nowadays they are referred to as public holidays which companies have to give to employees. Those who have to work of course are those in essential industries plus of course certain retail outlets they will be open and catering. Some factories for safety reasons where plant cannot be shut down also need skeleton staff of course.
All offices and factories that do not need to operate will be closed though on Monday.
If you are called in on one of those days traditionally employers are expected to pay you double time and if an emergency call in a call out fee. Today however employers (retail outlets) are getting clever and writing contracts of employment where some of these days are part of your normal working hours.
Most of these holidays were put on the statute book before there was a law in force as to how many days holiday an employer had to give you in fact at the time many of them came into force a normal working man probably go no holiday and had to work 6 days a week. Nowadays the average holiday in the UK is 5 weeks with government and large corporations giving 6 weeks. Often though most companies do stipulate when some of this holiday has to be taken such as Christmas and in some industries 2 weeks in August.
Thank you so much for the explanation, snugs. We have national holidays here, of course, but our typical annual vacation is two to three weeks.