Where was Mean Solar Time first adopted?

TL;DR

This paper revises the historical timeline of the adoption of mean solar time across European cities, highlighting earlier instances than traditionally cited, based on primary references.

Contribution

It provides a revised chronological account of when various European cities first adopted mean solar time, correcting previous assumptions.

Findings

England likely first adopted mean time around 1778-1779.

Geneva adopted mean time for horologists in 1778-1779.

Public clocks in Geneva appeared in 1821, later than previously thought.

Abstract

It is usually stated in the literature that Geneva was the first city to adopt mean solar time, in 1780, followed by London (or the whole of England) in 1792, Berlin in 1810 and Paris in 1816. In this short paper I will partially revise this statement, using primary references when available, and provide dates for a few other European cities. Although no exact date was found for the first public use of mean time, the primacy seems to belong to England, followed by Geneva in 1778-1779 (for horologists), Berlin in 1810, Geneva in 1821 (for public clocks), Vienna in 1823, Paris in 1826, Rome in 1847, Turin in 1849, and Milan, Bologna and Florence in 1860.