As an aside, standard times across a country or time zone were introduced comparitively recently.
Until the early 1800s each town, city or area kept its own “local time” which was synchronised only with the time indicated by sunrise/sunset. So noon in London would occur about twenty minutes before noon in, say, Exeter. “Leeds time” was six minutes behind London.
This presented no problems when journeys of any significant distance could be measured in many hours or even days. Then came the railways and as they expanded “local time” caused enormous problems with timetabling and scheduling.
In 1840 the Great Western Railway was the first railway company to standardise its time to Greenwich Mean Time. Others soon followed and the adoption of GMT by the railways led to the entire country using GMT as the standard time for the UK. There were pockets of resistance, mainly from the church and some church and cathedral clocks were fitted with two minute hands, one showing local time and the other GMT. In 1880 the Statutes (Definition of time) Act was passed and a unified standard time the whole of Great Britain was finally given legal status. In 1884 GMT was agreed as the universal reference for setting time around the globe.
Other countries followed a similar pattern, with the railways driving the need to adopt a standard time. Standard time in India was not adopted until 1906. Nonetheless some parts of the country refused to comply. Calcutta and Bombay continued to some degree with local times until 1945 and 1955 respectively.