The end of August brings us a bank holiday. It is the last public holday until Christmas.
I don’t believe it celebrates anything in particular, just the end of summer.
It used to be that banks and other shops closed on these days. Travel was disrupted. The world came to a halt.
Now it’s less so. You may find that some train lines are closed for engineering work. Museums or shops will probably be open, but do check. Transport sometimes operates a different, reduced service.
If you are visiting during the last weekend in August, and have plans, do double check your plans are not affected.