[NTLUG:Discuss] Slightly OT: Why would I care about Leap Seconds

[Chris Cox]

Leroy Tennison wrote:
> Fred James wrote:
>> All
>> Why would I care about Leap Seconds?  In the first paragraph at 
>> <http://cspry.co.uk/computing/Indy_admin/TIMEZONE.html> it says: 
>> "However, `TIMEZONE', as implemented in this way in IRIX, does not take 
>> into account leap seconds, nor changes made by the European Union and 
>> other bodies, in daylight savings time. The TIMEZONE settings have to be 
>> altered manually every year, to update them, as changeovers are often 
>> variable.**"  Do I care, and if so why?  No, I am not in the UK or 
>> Europe - I am in Texas.  Thank you in advance for any help you may be 
>> able to offer.
>> Regards
>> Fred James
>>
>> PS:  I am using TZ=CST6CDT5,M3.2.0/2,M11.1.0/2 to deal with the new 
>> rules and so far testing has shown it to work on SGI IRIX 6.*, and on 
>> Unisys UNIX SVR4 release 2.  I shall be testing on some Linux boxes soon.
>>
>>   
> Unless you are doing something esoteric and needing to keep in sync. 
> with other machines that are "leap second aware" I would ask the 
> question "Who cares about a second of deviation or even a minute?" Sure, 
> with NTP you can stay within a second or two of UCT and that's not a bad 
> idea but somewhere the "Get a life" sanity check needs to be introduced. 
> Of course, with a question like this, "Ask five experts, get six 
> answers" is probably going to apply.

Actually, using NTP you should be able to sync well within microseconds
of time from the server (close enough for almost anything to not care).

And time sync is VERY important.  There are many critical infrastructure
services that will not operate correctly unless all hosts are in
sync with each other.