But Astronomers don't actually use "Civil Time" they tend to use either UTC, TAI, or for the continuation of record keeping over the last several hundred years.

But Astronomers don't actually use "Civil Time" they tend to use either UTC, TAI, or for the continuation of record keeping over the last several hundred years... 'Terrestrial Time'... None of which match up with any Civil Time anywhere on the world, except UTC which does so only periodically for some European countries, and year round in the following countries which resist the idiocy of shifting their clocks around based on the Season: Burkina Faso, Côte d'Ivoire, The Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Mauritania, Tomé and Príncipe, Senegal, Leone, Togo, Western Sahara (not technically a country but that's unrelated to the currently customary timezone), Greenland, Iceland, Saint Helena, Ascension Island and Tristan da Cunha