If 12 is midnight or noon, then 12:00am has to be midnight. If 12:00am was noon, then 12:59am would be in the afternoon, which would be weird. Of course, having your clock start at 12 and then go to 1 is also weird.
Ask HN: What does 12:00 AM mean?
11–20 of 221 posts
Re: Ask HN: What does 12:00 AM mean?
#12I remember it like this: when it says 12:00 AM that means that the AM is getting started (midnight) and at 12:00 PM the PM is getting started (midday)
Re: Ask HN: What does 12:00 AM mean?
#13No post body was provided.
Re: Ask HN: What does 12:00 AM mean?
#14That sounds really frustrating. I'm sorry that happened to you.
Time is a hard programming and engineering problem. Adopting a global UTC on a 24 hour clock would resolve most of this, but people are entrenched.
Re: Ask HN: What does 12:00 AM mean?
#15If a time included either "AM" or "PM" then I would assume it was specified as 12h, not 24h.
Re: Ask HN: What does 12:00 AM mean?
#16Imagine 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.
Re: Ask HN: What does 12:00 AM mean?
#17When working at international companies that have little interaction between countries (i.e. not so much that it would be standardized, but enough that it would be an issue): eventually everyone learns to write dates and times in both ways (14:00 / 2pm, 4/12 / 12 April). The Europeans think that they're translating for the "dumb Americans who can't count higher than 12", the Americans think they're translating for the "quirky Europeans who have to do everything special".
But to your question, yes 12:00 AM is midnight. It's the 12 o'clock that's at/after midnight, while 12:00 PM is the 12 o'clock that at/after noon.
Re: Ask HN: What does 12:00 AM mean?
#18Look at an analog 12-hour clock. Ask yourself what the "natural" way to read it at midnight would be (what number is the hour hand pointing towards)?
Re: Ask HN: What does 12:00 AM mean?
#19I think it makes sense in a world where reading a clock face is common (12 gradations repeating twice is easier to read at a glance than 24 gradations), but in a modern world that is international and the primary timekeeper is a phone, I don't think it is defensible.
Re: Ask HN: What does 12:00 AM mean?
#20Quoted post unavailable.
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