A bank holiday is a UK public holiday, named for the days banks were legally closed under the Bank Holidays Act 1871. England and Wales get eight a year, Scotland and Northern Ireland slightly different sets. The same concept is a public holiday in Australia and New Zealand and a statutory holiday in Canada.
For multi-site workplace planning, the regional names matter less than the calendars: which office is closed when, and how attendance shifts around long weekends. The Tuesday after a UK bank holiday Monday is reliably the busiest office day of that week.