81–90 of 221 posts
"Up to late 1805 the Royal Navy used three days: nautical, civil (or "natural"), and astronomical. For example, a nautical day of 10 July, would commence at noon on 9 July civil reckoning and end noon on 10 July civil reckoning, with PM coming before AM. The astronomical day of 10 July, would commence at noon of 10 July civil reckoning and ended at noon on 11 July"
I've noticed that they no longer post 12:00am as a flight time. Instead it would be listed a few minutes before, like 11:55pm Nov.9.
Imagine if 12AM meant 12 noon. What would one second past 12 noon be? It'd have to be 12:00:01 PM. Even one millisecond past 12 noon would be PM. So "12AM" could only exist for an infinitesimal length of time, in contrast to 11AM, 10AM etc. which each last for an hour.
The way to remember this that finally clicked for me is that 'A' means 'ante', 'P' means 'post', and 'M' means Meridian some Latin word that means the sun is directly overhead. Or more practically speaking: noon. 12:00 PM is noon because one minute later, the sun is past being directly above. That is, it's 12:01 Post Meridiem. Since it would obviously be nonsensical for 12:00 AM to be immediately followed by 12:01 PM…
Does not make any sense at all. You jump from "sun is overhead in 12 hours" (12 AM) to "sun is overhead in 1 hour" (1 AM) when you follow that logic. The 12 hour-system is broken and should go away.
Ante meridium and post meridium. Ante- meaning “before”, meridium meaning “highest point of the sun” as in when the sun crosses the “meridian” which would be the line in which it is now setting instead of rising. Passing from post-meridian to ante-meridian is exactly 12 hours from when the sun passed the meridian point, to keep it “consistent”. I get though that it’s confusing, I questioned it a lot as a young boy. P…
It's like using metric. Just use it.
Earlier quoted context omitted.
I’m deploying on Friday night at 11:15pm Eastern or 5:15am in the UK.
We're discussing time formats. Some Europeans would complain when we'd write "I'm deploying on Friday morning at 10am Eastern or 3pm CET." instead of "15:00 CET"
Ante meridium and post meridium. Ante- meaning “before”, meridium meaning “highest point of the sun” as in when the sun crosses the “meridian” which would be the line in which it is now setting instead of rising. Passing from post-meridian to ante-meridian is exactly 12 hours from when the sun passed the meridian point, to keep it “consistent”. I get though that it’s confusing, I questioned it a lot as a young boy. P…