Archive for October 28, 2018

On The Alteration Of Time

Posted in History with tags , , , , on October 28, 2018 by telescoper

So here we are again, having put our clocks back an hour. Summer Time is over, but at least I had extra time to do this morning’s crosswords. Or so it seems. It’s really only the clocks that changed, not the time. But then what is time, other than what clocks measure?

Anyway, before I get too philosophical let me mention that I found the marvellous poster above on Twitter. It’s from 1916, when British Summer Time was introduced. I was surprised that the practice of changing clocks backwards and forwards began so recently in the United Kingdom. To be honest I’m also surprised that the practice persists to this day, as I can’t see any real advantage in it.

It would be better in my view to stick with Greenwich Mean Time throughout the year. Any institution or organisation that wants to change its working hours in summer can easily do so, but the world of work is far more flexible nowadays than it was a hundred years ago and I think few would feel the need.

Anyway, while I am on about Mean Time, here is a another poster from 1916.

Until October 1916, clocks in Ireland were set to Dublin Mean Time, as defined at Dunsink Observatory rather than at Greenwich. The adoption of GMT in Ireland was driven largely by the fact that the British authorities found that the time difference between Dublin and London had confused telegraphic communications during the Easter Rising earlier in 1916. Its imposition was therefore, at least in part, intended to bring Ireland under closer control and this did not go down well with Irish nationalists.

Ireland had not moved to Summer Time with Britain in May 1916 because of the Easter Rising. Dublin Mean Time was 25 minutes 21 seconds behind GMT but the change was introduced at the same time as BST ended in the UK, hence the alteration by one hour minus 25 minutes 21 seconds, ie 34 minutes and 39 seconds as in the poster.