Clock time is down to three things. The first was churches. Some of the most ancient clocks in the UK are in churches (the astronomical clock in Exeter Catherdal dates from around 1484, though its mechanism was replaced in 1885). Churches and monasteries had clocks so that the canonical hours and times of service could be accurately kept.

Then there was navigation. Accurate clocks were needed to determine longitude at sea. This led to the establishment of Greenwich Mean Time (GMT) as the reference for time zones and the basis for the modern Coordinated Universal Time (UTC).

Finally, there was the railway. When the lines were being built, and services timetabled, it was discovered that virtually every clock in Britain was out of sync with every other! The rail companies took a leaf out of the Naval book and insisted that all station clocks be harmonised with GMT so that timetables could be accurate. This ledv to church and town hall clocks being harmonised with the station clocks, whereupon factory, school and domestic clocks followed suit.

It is noticeable that Samuel Pepys, in his famous diary which covers 1660-1669, pays attention to the date, but seldom if ever mentions or refers to clock time, going to his office only when there is something to do.