What does "midnight" means?

[jim.sklansky]

I want to know exactly what does it mean by midnight. For example say: 1st February Friday midnight: it means what? The starting of the day (12 am of 1st february) or finishing of the day (12 pm of 31st January)??

[MyITGuy]

Midnight - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Midnight)

"In America, digital clocks and computers commonly display 12 a.m. for midnight."

So "The starting of the day (12 am of 1st February)" as you stated....however its always best to confirm with the client to ensure a deadline isn't missed.

[nealrm]

Midnight always refers to 12:00 in the middle of the night (24:00).

In the US, by tradition 12am is midnight and 12pm in noon. In truth neither is correct. AM and PM stands for after and post meridiem. However, at noon the meridiem is directly overhead and at midnight, the meridiem is directly down. So in both case the meridiem is neither post or after.

To avoid any confusion, many times 12:00:01 am is used instead of midnight.

[Freelancier]

From the NIST (http://www.nist.gov/pml/div688/times.cfm)web site:


Is midnight the end of a day or the beginning of a day?
When someone refers to "midnight tonight" or "midnight last night" the reference of time is obvious. However, if a date/time is referred to as "at midnight on Friday, October 20th" the intention could be either midnight the beginning of the day or midnight at the end of the day.

To avoid ambiguity, specification of an event as occurring on a particular day at 11:59 p.m. or 12:01 a.m. is a good idea, especially legal documents such as contracts and insurance policies. Another option would be to use 24-hour clock, using the designation of 0000 to refer to midnight at the beginning of a given day (or date) and 2400 to designate the end of a given day (or date).

Computers think that the day ends at 23:59:59.99999999 (depending on its clock resolution) and a new date starts on 00:00:00.0000000000.

[vangogh]

Obviously we need to define things like when the new day starts so we're all speaking the same language. I tend to think of the day starting when the sun rises (or more realistically whenever I wake up). It ends when I go to sleep (unless that's after the sun has risen). The few hours in between don't exist (unless something wakes me up temporarily).

I also think the new year should start with the first day of spring.

[billbenson]

I wonder what the legal definition is? Is 12 midnight the next date i.e. Feb 1 or is it still Jan 31?

[vangogh]

It's the start of the next day. On a 24 hour clock when the time is 00:00 it's 12:00 midnight on a 12 hour clock. As the click strikes midnight, the new day starts. That's why it's AM instead of PM.

[billbenson]

But is 00:00 legally the next day?

This is kind of like 1/0 = ???

[nealrm]

I think the question we are trying to resolve is Is midnight the start or the end of a day?​ From a practical standpoint, if you tell someone that a project will be done by Friday midnight do you have Friday day to work on it.

Looking around the web at different definitions and other conversations it is clear that midnight refers to BOTH the start of a day AND the end of day. So the term by Friday at midnight can and does have to two means. Military time does allow for a clearer interpretation. It has 24:00 for midnight at the end of a day and 0:00 for midnight at the start of the day. (but I am not sure if it is used that way in practice)

Because there is no clear conscious on the term, I would suggest not using it. Instead use 11:59 pm and 12:01 am.

[vangogh]

But is 00:00 legally the next day?

I was all set to dig in and say yes it is legally the next day, but I decided to do some research. Here's what I found at the The National Institute of Standards and Technology (NIST) site (http://www.nist.gov/pml/div688/times.cfm#midnight), which is an agency of the Department of Commerce.



When someone refers to "midnight tonight" or "midnight last night" the reference of time is obvious. However, if a date/time is referred to as "at midnight on Friday, October 20th" the intention could be either midnight the beginning of the day or midnight at the end of the day.

To avoid ambiguity, specification of an event as occurring on a particular day at 11:59 p.m. or 12:01 a.m. is a good idea, especially legal documents such as contracts and insurance policies. Another option would be to use 24-hour clock, using the designation of 0000 to refer to midnight at the beginning of a given day (or date) and 2400 to designate the end of a given day (or date).


So yes, 00:00:00 is the start of the new day, but it's also the same time as 24:00:00, which is the end of the previous day. Midnight refers to that instant in time when the day is switching over and can refer to either the old day or the new one.

I know Wikipedia is not necessarily the authority on most things, but here's what their page about midnight (http://en.wikipedia.org/wiki/Midnight) says



Midnight marks the beginning and ending of each day in civil time throughout the world. It is the dividing point between one day and another.


and



It is actually grammatically incorrect to use "a.m." and "p.m." when referring to 12:00


Midnight technically belongs to neither day. It's the exact instant between the two of them.

[Harold Mansfield]

This could easliy go round in circles like a Bugs Bunny Daffy Duck skit about this week being next week's last week, but midnight is a new day.

Online, in business, on a computer, in the military, at banks, and electronic devices (unless youy have changed the settings), midnight is the start of a new day. 11:59 p.m. is one day. 12:00 a.m. is the next day. Everything electronic goes to the next date on the calendar at 12:00 a.m.

When people say "by midnight", what they really mean is that 11:59 p.m. is the last possible minute.

[jim.sklansky]

Thanks all of you for your discussion on my question. So am i conclude the answer as:

1st February midnight means 11.59 PM Friday?

[Harold Mansfield]

Thanks all of you for your discussion on my question. So am i conclude the answer as:

1st February midnight means 11.59 PM Friday?
No because 11:59 is still Jan 31st.

It gets sticky when you put it like that. If someone says Wednesday at Midnight, it means they consider 12:00 a.m part of the same night. But it's still technically the next date.

For instance, I might say in conversation, "I went out Thursday night and didn't get home until 3 a.m.". We don't generally say, "I went out Thursday night and didn't get home until Friday at 3 a.m.".

Jim, where are you from?

[nealrm]

The term midnight is the point of time that one day ends and another begins. So it is part of BOTH days. Depending on a persons background they may consider midnight to be the start of the day or the end of the day. Either is correct. If you look at conversations across the web on the subject you will see that most people consider midnight to be the end of the day.

So if someone says 1st February at midnight, I would clarify what they mean.

[billbenson]

So if someone says 1st February at midnight, I would clarify what they mean.

When my mom said be home by midnight I didn't need clarification :)

[Harold Mansfield]

The only technical clarification is that the date changes to the next day at midnight on pretty much everything business and technology related.
If a payment is due on the 1st and you pay it that night at 12:01 a.m., you have paid it on the 2nd.

[billbenson]

The only technical clarification is that the date changes to the next day at midnight on pretty much everything business and technology related.
If a payment is due on the 1st and you pay it that night at 12:01 a.m., you have paid it on the 2nd.

Good point

[ozetel]

The technical limits are the benchmarks for me too - if we consider our industry and looked at routing a phone number on the basis of the "time of day", all settings are based on the "day of week" finishing at 11:59:59 and the new "day of week" beginning at 12:00, thus we look at 12:00 as the new day's beginning.

But well, very intriguing post that has captured some imagination that is for sure!

[tallen]

This has been an interesting discussion. Clearly a lot depends on context, which the opening poster hasn't really given us. I will point out that the OP asked what does "midnight" (the word) mean, not what does 12:00 (midnight) mean. Without further clarification, I am assuming that the OP is talking about a deadline, whether it's a deadline for making a payment, or a deadline for getting work done under contract. If I had a contract that said the work would be done by midnight on the 1st of February, my first take would be that the deadline is at the end of the day on February 1st (e.g. 11:59:59). But note my phrasing is different from that of the OP (by midnight on the 1st of February vs. 1st February midnight). A further complicating factor is that this is the first of the month, so maybe the implication is that the work needs to be done by the end of January? More context would certainly help in the interpretation....

[billbenson]

It does point out that the word midnight or noon should not be used in a legal agreement.

[vangogh]

Online, in business, on a computer, in the military, at banks, and electronic devices (unless youy have changed the settings), midnight is the start of a new day. 11:59 p.m. is one day. 12:00 a.m. is the next day. Everything electronic goes to the next date on the calendar at 12:00 a.m

That's for the benefit of the computer. It has to change over at some point. Midnight is technically the exact instant when the day is changing so it belongs to both days. It's neither AM nor PM since it can refer to either. Check the link I posted to the National Institute of Standards and Technologies, which I would think would be a good source.

[tallen]

Noon is much less ambiguous than midnight. For any given location on a given day, there is only one noon moment, whereas there are two possible midnight moments, one at 0000 hours and one at 2400 hours, the beginning and the end of the day.

[nealrm]

If we are going to state that electronic device are the standard, then we have a really huge problem. I have at least 4 different midnights throughout my house, plus 3 areas where it is constantly midnight (the electronic device just keeps flashing 12:00). This will make for one heck of a New Years party at some point.

[vangogh]

"Captain, sensors are picking up a temporal distortion in the living room."