explain xkcd - User contributions [en]

2266: Leap Smearing

2020-02-12T12:06:40Z

162.158.91.197: /* Explanation */

{{comic
| number = 2266
| date = February 10, 2020
| title = Leap Smearing
| image = leap_smearing.png
| titletext = Some people suspect that it started as a "No, I didn't forget Valentine's Day" excuse that got out of hand.
}}

==Explanation==
{{incomplete|Created by a SMEARED LEAP SECOND CALCULATING A TIP. Please check my calculations of the time if using the 10th February and evenly spread 24 hours over 28 smear-days. Do NOT delete this tag too soon.}}

Humans [https://en.wikipedia.org/wiki/Japanese_clock usually] measure time by regularly-sized intervals, but the natural world is not always so accommodating. Just like we add {{w|leap days}} every four years (except for years divisible by 100 but not 400) to prevent our calendars from drifting with respect to the seasons, we add {{w|leap seconds}} to the clock every now and then to prevent 12:00 PM from drifting away from solar noon. Unfortunately, Earth's day is not as regular as Earth's year, so leap seconds cannot be predicted with a formula but are instead added as needed, most recently in 2016. Officially, the leap second is added at midnight (so a clock will tick 23:59:59...'''23:59:60'''...00:00:00), but this is an extremely inconvenient edge case, to the point that there are many proposals to do away with leap seconds entirely (as of this comic strip's publication, the matter will be discussed in the World Radiocommunication Conference in 2023).

Rather than inserting an extra tick into timestamps and dealing with the resulting hiccups (e.g. programs hard-coded to expect that [https://infiniteundo.com/post/25509354022/more-falsehoods-programmers-believe-about-time#_=_ every minute will contain exactly sixty seconds]), {{w|Google}}'s services 'smear' the leap second over the course of a 24-hour period, officially called [https://developers.google.com/time/smear Leap Smear] by Google. The smear is centered on the leap second (at midnight) so from noon the day before to the noon the day after each second is 11.6 μs longer (1s/(24*60*60) = 11,574 μs). This difference is too small for computers to be bothered with, and by centering on midnight the difference in time will never be more than half a second at midnight; just before midnight it will be half a second behind, after midnight it'll be half a second ahead. This comic's joke arises from the idea of extending this practice to smearing leap days over the month of February. This comic strip was published February 10th, 2020, almost three weeks before the leap day on February 29th, 2020.

In the comic, [[Cueball]] is visiting one of Google's facilities, presumably during office hours and on the 10th day of February, when the comic was released. But when he looks at their clocks he sees they are all around 3:00 AM (which is in the middle of the night). He thus asks [[Ponytail]] and [[Hairy]] why their clocks are wrong. Ponytail tells him it is because of leap day smearing.

Ponytail explains that adding an extra day creates too many glitches. So they just run their clocks 3.4% slower during February. She thus states that it works approximately like leap smearing for seconds, so that the extra day's 24 hours are spread evenly out over the course of February, keeping it at the regular 28 days, but still running over 24*29 = 696 hours, even though their clocks only go through 672 hours = 24*28.

Thus the 24 hours less to count are spread out over the 696 real hours, which means their clocks run 24/696 = 3.445 % slower (matching the 3.4% Ponytail mentions). Every smeared day will thus be about 0.86 hours longer (24/28) than a standard day. So when day-smearing clocks read 3:02 AM on February 10th (the comic was released on February 10th), about 9.1264 smeared days will have passed. This translates to about 9.4523 standard days (9.1264*29/28), which is approximately 10:51 AM on February 10th, well within normal working hours.

The idea would of course, contrary to leap second smearing, be very inconvenient for those following it, due to the fact that it would be out of sync with the rotation of the earth for most of the course of the month. And also with all their local business partners. (Of course it would mean they would sync up better with some of their partners abroad, see [[1335: Now]].) A different kind of time-smearing was looked at in the far earlier comic [[320: 28-Hour Day]], which was actually designed with a form of convenience in mind, and it would be interesting to see what the results could be of creatively combining both systems.

The title text humorously suggests that some people (at Google) suspect that the real reason for the leap day smearing was actually a "No, I didn't forget Valentine's Day" excuse that got out of hand. [[Randall]] has some issues with [[:Category:Valentines|Valentines]], see for example [[1016: Valentine Dilemma]]. This comic was released four days before {{w|Valentines Day}} of 2020. It was the first time in 8 years he made any reference to Valentine around this time of year, but the seventh time in total. Interesting to see if he also releases a Valentine related comic on Friday of the week, as that falls on Valentine Day February 14th 2020.

The idea is, that maybe a CEO at Google forgot to buy something for his Girlfriend for Valentine, and thus tried to suggest that it was not because he forgot, but that at his work it was still February 14th. Presumably, in February 2016, he used this excuse to buy himself 12 extra hours (as the end of a smeared Feb 14 is exactly halfway through the month) to get his girlfriend a present, and then required the company to actually implement "leap day smearing" by 2020 to maintain the illusion.

==Transcript==
:[Cueball, Ponytail, and Hairy are looking up at a digital clock on a wall. It displays the time in white on a black background, with a logo on the frame beneath the time.]
:3:02 AM
:Google

:Cueball: Why do the clocks say it's 3AM?
:Ponytail: Adding an extra day creates too many glitches. Instead, we're just running our clocks 3.4% slower during February, to avoid the irregularity.

:[Caption below the panel:]
:This year, Google has expanded their leap second "smearing" to cover leap days as well.

{{comic discussion}}

[[Category:Valentines]] 
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Time]]

Talk:2249: I Love the 20s

2020-01-01T19:00:23Z

162.158.91.197:

But is White Hat right or wrong? [[Special:Contributions/162.158.91.197|162.158.91.197]] 19:00, 1 January 2020 (UTC)

1995: MC Hammer Age

2018-05-21T05:16:21Z

162.158.91.197: /* Explanation */ blank

{{comic
| number = 1995
| date = May 18, 2018
| title = MC Hammer Age
| image = mc_hammer_age.png
| titletext = Wait, sorry, I got mixed up--he's actually almost 50. It's the kid from The Karate Kid who just turned 40.
}}

==Explanation==

This is the first comic to combine the [[:Category:My Hobby|My Hobby]] series with the theme of listing facts that [[:Category:Comics to make one feel old|make one feel old]].

In the comic [[Cueball]] (as [[Randall]], as it is his hobby) is asking [[White Hat]] if he wants to feel old. (This exact opening phrase was used by [[Megan]] in [[1898: October 2017]]). Cueball doesn't wait for an answer, though like Megan did, but tells White Hat that {{w|MC Hammer}} just turned 40. Surprisingly, at first, this doesn't really make White Hat feel old, he actually feels this is rather normal (compared to his own age). MC Hammer is a pop rapper/singer who was most popular in the early 1990's for ''{{w|U Can't Touch This}}'' with the catch phrase ''{{w|Hammer Time|Stop: Hammer Time}}'', and {{w|hammer pants|shiny}} {{w|baggy pants|baggy}} pants often incorrectly referred to as {{w|parachute pants}}.

So at first it seems that Randall's attempt to make White Hat feel old has failed miserably. However in the caption Randall explains that this is part of his hobby. By "lowballing" the facts to begin with he can make people feel really old when he tells them the truth, so they learn that the correct number (age/years ago, your age at the time etc.) is even worse than the first opening statement.

In the title text he then tells White Hat the "truth": "Wait, sorry, I got mixed up--he's actually almost 50. It's the kid from The Karate Kid who just turned 40." So this suddenly adds ten more years to MC Hammers age, and that little kid from the Karate Kid movies... is he already 40 years old. Now White Hat probably feels a bit old. In the original {{w|The Karate Kid}} (the first 3 movies) {{w|Ralph Macchio}} was the actor who starred as Karate Kid. And he seemed so young...

The real blow, comes when White Hat (and most likely the reader), now intrigued goes home and looks these two people up on Wikipedia. Ralph Macchio was already much older than the kid he portrays in the movie, a school kid - [https://www.imdb.com/title/tt0087538/trivia?item=tr0565736 he was 22 years old] when shooting the first movie. On the day this comic came out, both MC Hammer and Ralph Macchio were both 56 years old. And Ralph is the older one of the two being born in 1961, while Hammer was born in 1962.

So even in the title text, the corrections are both "lowballed" facts, so still preserving the maximum effect while adding more credibility to the claims, so people already start to feel old before the last 6 years is added to Hammer's and 16(!!) years to Macchio's age.

Of course, this is assuming they ''do'' look it up, and if they believe Randall the first time, there is no reason to assume this will happen. However, then they probably already feel old from the first correction.

Note that in the other ''make one feel old'' comics Randall did not apparently indulge in this new hobby of lowballing facts. As far as we can tell, those were all accurate for the time the comic was created. But if this is a new hobby, we may need to examine newer "feel old" comics extra carefully from now on. (If we want to feel even older that is.)

==Transcript==
:[Cueball and White Hat are walking together.]
:Cueball: Want to feel old? MC Hammer just turned 40.
:White Hat: Wow.
:White Hat: I mean, I guess that's not too surprising, right?
:White Hat: It's been a long time.

:[Caption below the panel:]
:My hobby: Deliberately lowballing "Want to feel old" factoids to set up a bigger payoff later when they learn the correct number.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Comics to make one feel old]]
[[Category:My Hobby]]