Editing 376: Bug

{{comic
| number    = 376
| date      = January 28, 2008
| title     = Bug
| image     = bug.png
| titletext = The universe started in 1970. Anyone claiming to be over 38 is lying about their age.
}}

==Explanation==
In computer systems, time is measured starting from some arbitrarily chosen point. That particular time is known as the "{{w|Unix time|epoch}}" for that system. The {{w|UNIX}} operating system internally uses an epoch of January 1, 1970, and measures the time as a number of seconds from then. Since this was intended only for things internal to the OS (File last modified times and the like), using 1-Jan-1970 was safe as no UNIX systems existed before that date.

However, since UNIX included a number of system functions to manipulate these dates, some developers mistook them for a general purpose date object, and misused them in applications requiring dates before the epoch, by using negative values.  Such usage would inevitably fail; for example, since the value isn't specified to be signed or unsigned, the date might be considered to be far in the future, instead of in the past.

[[Cueball]] has clearly misused the system date in some way (probably by using an unsigned data type to store the timestamp, which cannot store negative values (in this case dates before 1970) or doing some other operation that doesn’t support negative values). His friend makes a pun by combining "Epoch" with "Epic Fail" - a colloquial term meaning "a very big mistake was made."

Another problem using the UNIX system date as a general purpose date object is commonly known as the {{w|year 2038 problem}}. At 03:14:08 on 19 January 2038, the 32-bit versions of the Unix time stamp will cease to work, as it will overflow the largest value that can be held in a signed 32-bit number. The 64-bit version "will" expire at 15:30:08 on 4 December 292,277,026,596.

The title text takes the joke to the next level, claiming that the entire universe began when Unix did, and therefore no one could have been older than 38 at the time when the comic was released in 2008. The formula is 'x - 1970', where x is the current year, which would explain the bug, since no earlier dates are possible. This is also similar to {{w|Last Thursdayism}}.

An example of this 2 to the 32nd power time overflow problem includes the {{w|Deep_Impact_(spacecraft)#Contact_lost_and_end_of_mission|Deep Impact spacecraft}}, which, on August 11, 2013, 00:38:49 (more than five years after the comic), was 2 to the 32nd power tenths of a second from January 1, 2000. There is speculation that a system on the craft tracked time in one-tenth second increments since January 1, 2000 and stored it in a signed 32-bit integer, which then overflowed at some point, similar to the Year 2038 problem.

==Transcript==
:[Cueball sits at a computer, staring at the screen and rubbing his chin in thought. A friend stands behind him.]
:Cueball: Weird — My code's crashing when given pre-1970 dates.
:Friend [pointing at Cueball and his computer]: Epoch fail!

{{comic discussion}} 
[[Category:Comics featuring Cueball]]
[[Category:Computers]]
[[Category:Programming]]
[[Category:Puns]]