Time keeping history

Before the invention of wristwatches and smartphones, knowing the exact time wasn’t so simple—and in one part of London, you actually had to *pay* to find out what time it was. Meet Mrs. Greenwich, a woman famously associated with Greenwich Mean Time (GMT), who quite literally made a living by telling people the time. She inherited this unusual profession from her family, who lived in the town of Greenwich, just outside of London, and ran this "time-telling" business from the early 19th century until as late as 1943.

For a small fee, people were allowed to look at her clock to set their own watches or simply learn the time of day. In an era before standardized timekeeping, this was not just a service—it was a necessity. The Greenwich family’s timekeeping became so precise and respected that GMT was named after their town, eventually becoming the global standard for time measurement. Zero hour—00:00 GMT—starts right in their backyard, at the Prime Meridian running through Greenwich.

From this central point, time zones around the world are calculated. Traveling east from GMT, every country adds an hour—so Pakistan is +5 hours ahead of GMT. Go west, and each zone subtracts an hour. For example, if it’s midnight in Spain or Morocco, it’s 5 a.m. in Pakistan, 10 p.m. in Australia, and only 5 p.m. the previous day in the U.S. and Canada. Time really is relative—and thanks to Mrs. Greenwich and her legendary clock, we’ve been able to measure it with precision for centuries.

(Repost not my original)