Victorian London - Publications - Etiquette and Advice manuals - appropriate hours for visiting and dining

VISITING. -The proper hours for making calls at private houses are from 2 to 6 at the "West End." A letter of introduction should be left in person with a card and address, or at least delivered with a card by a messenger, and not sent by post.
The dinner hour in England for the professional and upper classes varies from 6 to 8 P.M. Guests should arrive not later than a quarter of an hour after the time named, but never a minute before it. In England the gentlemen never hand the ladies from table, but remain by themselves.

Murray's Handbook to London As It Is, 1879