"Roland Perry" wrote

In London in the 40's you could post a letter in the morning informing
someone you'd be round for afternoon tea. By the 70's you could still post
a letter at 9pm in a town in the Southeast and expect it to be delivered to
someone in another town by 8am.

In 1970 I could post a letter at the main post office in Oxford up to
midnight and it would be delivered in South East London at breakfast time.

Peter