Since ancient times, though the day has been divided into 24 hours, each hour has not always had 60 minutes, as we measure them.

The ancient Greeks divided the daytime into 12 hours, but they measured a day from sunrise to sunset. So, the longer a day was, the longer was each hour in it.

In Rome, too, there were no minutes, and each hour varied with the length of the day. On the shortest day of the year, a daytime hour had only about 441/2 minutes, while a night hour had about 751/2 minutes.

And on the longest day of the year, the measurements were reversed, and each daytime hour had 75.5 minutes!