I’ll start with a couple I’ve found for keeping up with atomic clock time, but this question isn’t limited to timekeeping, it can also relate to celestial events, weather, etc…

I do like the sleek and streamlined time.ms site, but according to their whois data, they only started that site a couple months ago, while time.gov has been around since 1999.

Long standing sites are preferable, but either way, what other live data sites do you people recommend?