A Time of Day Constitutes a Boundary Between Periods of Time

Today I’d like to advance a simple but ill-understood concept: A time of day isn’t a period of time. Instead, it’s a boundary between the period of time that comes before and the period of time that comes after.

So if a contract states that a given deadline is midnight at the end of March 13, 2012, the deadline will pass once the last second of the 11:00 p.m. hour expires and the first second of the 12:00 a.m. hour begins. Midnight is the boundary between those two seconds.

It seems that many drafters don’t understand that. That might be why so many contracts use “12:01 a.m” and “11:59 p.m.” as deadlines, rather than “midnight,” the implication being that when you state a time of day, you’re in fact referring to a minute-long period of time. That’s illogical. (Of contracts filed on the U.S. Securities and Exchange System’s EDGAR system in the past year, 467 contracts use “12:01″; 678 use”11:59”; and 452 use “midnight.”

It might be that drafters use “12:01 a.m” and “11:59 p.m.” so as to avoid the ambiguity in “midnight”—every day has two midnights, so if you just say “midnight,” it wouldn’t be clear which midnight you’re referring to.

But you can resolve that ambiguity by saying “midnight at the end of” or “midnight at the beginning of” the day in question.

And more to the point, 114 contracts filed on EDGAR in the past year use “5:01,” even though “5:00 p.m.” and “5:00 a.m.” aren’t subject to the same ambiguity as “midnight.” That suggests that many drafters who use “12:01” and “11:59” are in fact doing so because they think that a time of day refers to a minute-long period of time.

So if you’re lopping a minute off or adding a minute on your contract deadlines, I suggest that you stop doing so. It doesn’t make sense, and it risks muddying the waters for the rest of us.

About the author

Ken Adams is the leading authority on how to say clearly whatever you want to say in a contract. He’s author of A Manual of Style for Contract Drafting, and he offers online and in-person training around the world. He’s also chief content officer of LegalSifter, Inc., a company that combines artificial intelligence and expertise to assist with review of contracts.

24 thoughts on “A Time of Day Constitutes a Boundary Between Periods of Time”

  1. Ken, I agree but I suspect people sometimes say 12.01 am instead of 12.00 am, and are worred about the ambiguity of the latter.  Or they may be concerned about whether midnight is at the end or the beginning of a stated day as you suggest.  12.01 am is an inelegant quick fix.

    • Mark: Yes, I acknowledged as much in my post, but the popularity of “5:01” suggests that plenty of people who use “12:01” and “11:59” have something on their mind other than ambiguity. Ken

  2. Why not just say “12:00:00 a.m.”?  Or perhaps “11:59:59 p.m.”?  The ambiguity exists because there is a smaller measurement of time (seconds) than the contracts are referring to, so just break the time down into its smallest component.

    • CDW: As a matter of logic “12:00 a.m.” is incorrect. Midnight isn’t of the nighttime or morning hours—it’s the boundary between them.
      And you’re continuing to assume that a time of day is a period of time. By any logical analysis, it isn’t. So saying “12:00:00” or “11:59:59” simply represents an attempt to diminish the consequences of fallacious thinking. Heaven preserve us from “12:00:00” or “11:59:59.” The world has done just fine without them until now.

      • Ken, CDW has actually touched on a very interesting question, and he may be closer to being correct than you think.  The question is whether time flows in a continuus or in small quanta, and it’s not such a crazy idea that there is truly a point at which time cannot be subdivided any further.  If so, it means that “midnight” really is a discrete block of time, not a boundary between two periods of time.  But that’s an issue for physicists, not lawyers.  http://itotd.com/articles/582/quantized-time/

      • I disagree with the statement that “[a]s a matter of logic ’12:00 a.m.’ is incorrect.”

        “12:00 a.m.” means “exactly twelve hours before noon.” Nothing illogical about that.

        Referring to midnight as a “boundary” doesn’t clarify anything, because every point in time is a “boundary” between all the points that precede it and all those that follow it. Midnight’s nothing special in that respect.

        Time’s a mysterious thing, as Mike says. If time dilates, do the durationless points get bigger, or are there more of them? Any physicists out there?

        • I respectfully disagree with your assertion that “ A time of day isn’t a period of time.” Every midnight contains 60 seconds for e-filing in my jurisdiction. There are no seconds. File-marked midnight, it’s on deadline.

  3. I have seen (in documents drafted by my firm, alas) an existing service contract set to terminate at 12 midnight, and its replacement set to commence at 12.01 am. There was no intention to leave a minute’s gap…

  4. I can generally avoid the need to refer to a time to draw the boundary between two consecutive days, but when I can’t I generally use 11:59 pm or 12:01 am to avoid the ambiguity of “midnight.”  I have no problem with “midnight at the end of December 31, 2012” — other than it takes a few more words.  I wonder if “midnight” really adds anything to that formulation — why not simply “at the end of December 31, 2012”?  Possible confusion with the end of the calendar day and the end of the business day?

    I can’t recall encountering a situation where the minute’s difference between the true boundary between two days and the 11:59 pm approximation of it made a difference, but the minute gap between two contracts that Westmorlandia describes would drive me crazy!  And reducing the minute-long gap to a second-long gap by using 12:00:01 am wouldn’t help at all.

    For what it’s worth (probably not much, unless, maybe, you’re contracting with the U.S. Government), the GPO Style Manual says midnight is 12:00 am and noon is 12:00 pm.  http://www.gpo.gov/fdsys/pkg/GPO-STYLEMANUAL-2008/html/GPO-STYLEMANUAL-2008-14.htm

    Finally, I can’t imagine a reason to use 5:01 pm, unless that’s truly a precise time dictated by something beyond my control.

  5. There are points in time and periods of time. Points in time have no duration.

    If a contract expires at the end of June 30, the simplest way to express it is to say it expires and the end of June 30. Reference to the second or final midnight, or the midnight at the end of the day, involves mention of “midnight” needlessly.

    If you want to emphasize that the deadline is midnight rather than noon or the close of business at 5 p.m., you can say “at midnight at the end of June 30.” Without that special goal, the reference to midnight is unnecessary.

    There is a gap between logic and usage that has to be respected until logicians rule the world: logically there is but one noon per day, and two midnights, one before noon and one after noon on any given day. 

    In logic and language, the midnight before noon on any given day is 12 a.m., and the midnight after noon on that day is 12 p.m. 

    To refer to noon on a given day as “12 p.m.” (12 after noon) makes no more logical sense than would referring to midnight as “twelve hours after midnight.” Yet that is the convention.

    One last note on logic before shifting to actual usage: just as every day has two midnights, every midnight has two names. “Midnight at the end of June 30” is the same durationless point as “midnight at the start of July 1.”

    Now actual usage: for no reason I have ever been able to discover, the convention is that “12 a.m.” means “midnight at the start of the day in question” and the “12 p.m.” means “noon on the day in question.”

    Because of the ambiguity of “12 p.m.” (logic or convention?), I never use it in contracts. I just say “noon on [date]” if I mean noon, and “the end of [date]” if I mean the second midnight on a date. I could with equal clarity say “midnight at the start of [date plus one],” but it seems more intuitive to use that formulation for the start of a period than its end. 

  6. Sorry I am late finding this (but thanks Ken for posting the link to it). If you use the 24 hour clock, the time at midnight can be stated unambiguously: no need to worry about whether 12am or 12pm is a valid measure. Every day has a 00:00:00 hours and a 24:00:00 hours, which happen to be the same instant on successive days. But this opens up a whole different issue about using the 24 hour clock …

  7. I know this is an old post, but I was wondering if anybody has a case where the one minute gap was an issue? What if the lease expired at 11:59, but there is a renewal amendment already signed beginning as of the next day, and an explosion occurs at 11:59:30? Is there a lease in effect or not? Or is there no lease during the one minute gap?

      • Maybe. Any law school professors out there wanna give it a shot? ;-). While it may be a longshot, in my experience working here it’s going to be an issue one day and I’ll have to figure it out. I try to use “midnight at the end of X” as much as I can, but some lawyers just don’t get it and switch back to 11:59 am. Because of this, I’ve actually written lease renewal amendments that begin at 11:59 am the last day of the month to ensure there isn’t a minute gap. Anyway, I didn’t think anyone would know of a case, but it sure is an interesting concept.

  8. so, if my contract says, “to cancel this transaction, mail cancellation notice not later than midnight of November 09, 2015, do I have up until 11:59:59 pm of Nov 9th to postmark my cancellation? Or must I postmark my cancellation on or before Nov 8th, 2015?

    • It’s ambiguous, because there’s a midnight at both ends of a day. But I’d forget about referring to 11:59:59. Midnight is a point in time, not a period of time, so if you have until midnight to do something, you can do it in the last second of the preceding day.

  9. Sorry to dig up an old article, but it was near the top of a recent Google search I made trying answer a question I had about this.

    12 CFR 1026.23(a)(3)(i) states that “The consumer may exercise the right to rescind [a credit transaction] until midnight of the third business day following consummation, delivery of the notice required by paragraph (b) of this section, or delivery of all material disclosures, whichever occurs last”

    Here the usage of midnight seems ambiguous to me, since they didn’t use a timestamp or the phrase “at the end/beginning of”, so they theoretically could be referring to the moment when the clock strikes 00:00 of the third business day (which is in the beginning).


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