Talking about the test card made me think. It's interesting to consider that not all that long ago the sum total of available TV was...
BBC1 - not sure what time it started, but certainly not all that early prior to breakfast TV...ran through til around midnight when it shut down for the night
BBC2 - bulk of daytime was the test card. Late afternoon and evening programming, and shutdown around same time as BBC1. Maybe some Open University programming (very) early morning or late at night
ITV - Similar to BBC1 as I recall
Later, Channel 4 launched but it didn't come on until late afternoon, and also shut down at night.
Makes you realise why breakfast TV and the launch of Channel 4 were such huge events. Especially in the case of the latter they represented a significant increase in the overall amount of programming available..