I'm surprised that they were even using the 24hr clock over there.
If the system also knows about dates then the two ways would reduce to the same internal representation assuming 24:00:00 is correctly the end of day 1 and 00:00:00 the start of day 2. A system that doesn't have at least a basic understanding of dates would struggle with any time calculation going through midnight, but could get an answer of sorts by doing a modulo 24hr on all answers.
That would be stupidly complicated to do.
No. 00:00:00 (or 24:00:00) is an instant in time, the boundary between one day and the next, and has zero duration. The first minute of the day is the period from 24:00:00 to 00:01:00.
I would put it that the last minute of one day is from 23:59:00 and 24:00:00; and that the next minute, which is first of the next day, is from 00:00:00 to 00:01:00.
At the moment, we have the confusion of referring to the same time on two different days (without clarity of which day is meant)...
From Wikiversity here. If you want a real world example, look up the times for trains in Tanzania on the main network (that is not Tazara or the new standard gauge line). I guess it works for them.
I just checked on Google and Tanzanian time is 3hr ahead of UTC, so if this time system is in use then it is alongside another one which is 6hr different. The attached timetable doesn't say which, so working out whether an Amtrak train is AM or PM is going to be a cakewalk compared with trying to catch a train in Dar es Salaam.
I would say it'll be more likely late afternoon in Oxford.
12am is the morning, 12pm the afternoon - I’m just amazed that some are confused - possibly by not being ‘clever’ enough to know what AM and PM actually mean?
Perhaps they missed that day of school?
The problem comes when we understand the difference but the person writing the content doesn't. Hopefully that's a rare scenario.
They're using the same logic as they do for their normal 12 hour clock (which would have showed that hour as 12:00:00 to 12:59:59...)
AM stands for ante meridiem, Latin for Before Noon. PM stands for post meridiem, Latin for After Noon.
The standard argument is that time is always rounded down. So 12:00 is taken to include the period 12:00:00.00...1 to 12:00:59.99...9 which are all after noon.
Which, to be fair - is reasonable (unlike their use of M/D/Y compared to D/M/Y). When in the US a bought a 24hr flip clock that echoed my experience in the station. The box said it was in ‘Military Time’ format.
That's fair enough, and as soon as it's an instant after 12:00:00 then it's clearly PM. But that doesn't mean that the wording of AM or PM helps when only 12:00 is being referred to.
Others may disagree but I'm fully with you on this.
In other places on the railway, 23:59 goes to 24:00 goes to 24:01 etc
Is this just the American example mentioned upthread or are there systems in the UK that do this, and if so which ones?
If I recall correctly, but would have to check, the timetable data does this. Certainly some downstream systems (which contain fairly raw data derived from it) do. Times being scoped to the day the service departs it's origin station, so if it crosses midnight on its journey you enter hours 24, 25 etc
Indeed - am is the forenoon, pm the afternoon. Those are the literal translations of the Latin phrases of which which am and pm are the abbreviations.
The problem with that logic is that 1am doesn't mean "one hour before noon".
Yes, especially given xx:yy actually means xx:yy:-30 (and sometimes up to several minutes negative at London termini and Blackpool North).
