This just shows how much I rely on the web. It's nearly always my first port of call, even when there are far easier resources.
It's Saturday morning. I'm sitting here in Marcus's kitchen, using his laptop. I wonder what time it is. According to the clock on his computer, it's quarter-to-nine. At night. In 1904. The logical thing would be to go into the bedroom and look at the time on my mobile, or switch on the telly, or phone 123. But no, I endeavour to find the correct time on the web. Which I do, at The World Time Server.
Marcus could clearly use their free utility which keeps your computer's clock synchronised with the Atomic Clock, but it's Windows only.