# When is midnight?

**URL:** <https://boards.straightdope.com/t/when-is-midnight/53114>\
**Category:** Factual Questions\
**Created:** [February 4, 2001, 6:48pm UTC](https://boards.straightdope.com/t/when-is-midnight/53114 "2001-02-04T18:48:35Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![Ripley](https://avatars.discourse-cdn.com/v4/letter/r/74df32/32.png) [@Ripley](https://boards.straightdope.com/u/Ripley)\
**Post date:** [February 4, 2001, 6:48pm UTC](https://boards.straightdope.com/t/when-is-midnight/53114/1 "2001-02-04T18:48:35Z")

</div>

Is “midnight Wednesday” between Tuesday and Wednesday or between Wednesday and Thursday? First thought is the latter, but if midnight is 12:00 AM, than it’s the former, right?  
Isn’t 12:00 AM Wednesday midnight? Is it Tuesday’s “midnight”? Shouldn’t 12:00 AM belong to the same day as 12:01 AM?  
Is New Year’s Eve midnight Jan. 1st at 12:00 AM? Then “December 31st’s midnight” is between December 31st and Jan. 1st, eh? So what is 12:00 AM December 31st? – midnight Dec. 30th?  
When do laws effective at midnight take effect? (i.e what day?)

---

<div class="post-metadata">

**Author:** ![Stupendous\_man](https://avatars.discourse-cdn.com/v4/letter/s/a8b319/32.png) [@Stupendous\_man](https://boards.straightdope.com/u/Stupendous_man)\
**Post date:** [February 4, 2001, 7:45pm UTC](https://boards.straightdope.com/t/when-is-midnight/53114/2 "2001-02-04T19:45:33Z")

</div>

Midnight is 00:00. This time is the beginning of a new day, not the end of a previous one. The previous day ends at 23:59

So Wednesday at mignight _should_ be the beginning of Wednesday at 00:00, but since so many people get confused by this, you have to ask if they mean the end of Tuesday or not…

---

<div class="post-metadata">

**Author:** ![bizerta](https://avatars.discourse-cdn.com/v4/letter/b/3be4f8/32.png) [@bizerta](https://boards.straightdope.com/u/bizerta)\
**Post date:** [February 4, 2001, 7:47pm UTC](https://boards.straightdope.com/t/when-is-midnight/53114/3 "2001-02-04T19:47:12Z")

</div>

If you go read the fine print, you’ll find that most laws (and insurance policies, etc.) do not start at midnight; they start at 12:01 a.m. I know many of you disagree, because you have your own convention. However, there is not such time as 12:00 pm (it’s either 12 noon or 12 midnight). And midnight is the instant between two days so “Midnight, January 21st” does not exist. The 24 hour clock removes this ambiguity because 24:00 on Monday (which is also 00:00 on Tuesday) is not confusing.

---

<div class="post-metadata">

**Author:** ![AWB](https://avatars.discourse-cdn.com/v4/letter/a/bb73d2/32.png) [@AWB](https://boards.straightdope.com/u/AWB)\
**Post date:** [February 4, 2001, 9:54pm UTC](https://boards.straightdope.com/t/when-is-midnight/53114/4 "2001-02-04T21:54:10Z")

</div>

The 12:01 am clause is to assure that whoever signs a contract understands exactly what calendar day it is to be enacted. That is, 12:01 am Tuesday is definate; midnight Tuesday can be taken two different ways.

---

<div class="post-metadata">

**Author:** ![Jman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jman/32/4416_2.png) [@Jman](https://boards.straightdope.com/u/Jman)\
**Post date:** [February 5, 2001, 4:38am UTC](https://boards.straightdope.com/t/when-is-midnight/53114/5 "2001-02-05T04:38:44Z")

</div>

Cecil discusses midnight in [This Article](http://www.straightdope.com/classics/a1_130.html)

Jman