[LINK] Banks online and the end of daylight time

[Bernard Robertson-Dunn]

On 1/04/2010 11:08 PM, Kim Holburn wrote:
> I can't tell you about windows servers (which I think have an internal
> clock which uses local time ... shudder) but I have in the past had
> issues with databases.  *nix servers nearly always use GMT internally,
> so time zone changes forward or back only are referenced when the
> times are converted for viewing.  Databases though can have timestamps
> that could be local time.  Perhaps this is a matter of how they were
> programmed.  Databases generally don't like finding entries that have
> future time stamps, tends to upset them.  Turning everything off for
> the hour might be easier.  Of course turning them off for an hour
> probably means backing up, bringing everything down gently in the
> right order, then bringing everything back up again in the right
> order, could take quite a bit longer than an hour.
>
>    
Most mainframe sites I've been associated with take advantage of the end 
of daylight saving change.

The easiest is to just not process any transactions during the 
3:00-2:00am time change. They don't bring the system down, they just 
stop transactions from happening. That means they don't have any 
ambiguous transactions in local time (It's easier to program in local 
time than GMT or something else, similar).

Operations people often take advantage of this window, extend it a bit 
and do other systems maintenance activities. Hence the 2:00am-5:00 am 
window Westpac and CBA have gone for. Lots of government sites do 
exactly the same.

There are of course organisations like Qantas and other airlines and 
that can't do that, so they work on Coordinated Universal Time (UTC) 
that they get from Stratum devices.

See
http://en.wikipedia.org/wiki/Coordinated_Universal_Time and
http://en.wikipedia.org/wiki/Network_Time_Protocol
for descriptions.

> On 2010/Apr/01, at 9:09 PM, Rick Welykochy wrote:
>
>    
>> Gentle Linkers,
>>
>> A thread has arisen on the SLUG list regarding the fact that both the
>> CBA and Westpac banks announce on the their online banking sites that
>> they will be offline from about 2:00 AM to 5:00 AM Sunday during
>> the end of daylight savings time. You know, that hour that jumps
>> backwards.
>>
>> The suggested reasons for this include normal system maintenance
>> (coincidence?),
>> their Windows-based web servers not handling the changeover
>> properly, or worse
>> still, the behaviour of their (archaic?) back-end systems is unknown
>> when 3:00 AM
>> marches back to 2:00 AM.
>>
>> Does anyone with banking experience actually know how well modern
>> banking functions during the daylight savings dropoff?
>>
>>   * do ATMs continue to function? perhaps in an offline mode?
>>   * how about bank-to-bank transactions?
>>   * and the myriad of international-to-domestic connections and
>> transactions?
>>
>> Enquiring idle Easter minds want to know!
>>
>>
>> cheers
>> rickw
>>
>>
>> -- 
>> _________________________________
>> Rick Welykochy || Praxis Services
>>
>> Hofstadter's Law. "It always takes longer than you expect, even when
>> you take into account Hofstadter's law."
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>>      
>    
>
>
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-- 

Regards
brd

Bernard Robertson-Dunn
Canberra Australia
brd at iimetro.com.au