After hacking our way with blunt machetes through the information-dense breakdown of the Celestia’s triple-time display, we now come to the most interesting part by far of the Celestia — solar time as represented by a running equation of time hand adjusted to the tropical year. (Standard YMMV disclaimer: my list of Most Interesting Things has been known to cure chronic insomnia. Proceed with caution and Red Bull.)
For all those reasons previously mentioned, solar time isn’t exactly the most consistent thing on the planet. Sometimes it’s late, sometimes it’s early — it’s only ever on time four times a year. But that’s okay, we all got friends like that, and we love them anyway.
Now these deviations aren’t really that big a deal when taken on their own — the longest solar day is about 30 seconds longer than a mean solar day, the shortest solar day is about 21 seconds shorter than a mean solar day.
However, let’s imagine you get a whole run of solar days, each of them just a few seconds longer than a mean solar day. That difference of a few seconds starts to stack up real quick. One day you realise that, although your beautiful and accurate Swiss watch tells you it’s noon, the sun in the sky essentially DGAF and is like a whole quarter of an hour away from reaching its celestial zenith. Shock and horror!
That said, if your beautiful and accurate Swiss watch happens to be the Vacheron Constantin Celestia (please don’t make me type out its full name), there will be no shock and there will be no horror. You have a truly excellent polished pink-gold hand tipped with a splendid roseate sun, co-axial with the hours and minutes hands, indicating exactly how far the solar day is running ahead or behind civil time. Yay, science!