RE: Epics Archiver Appliance requests and DST/Timezones

[Abdalla Ahmad via Tech-talk <tech-talk at aps.anl.gov>]

Hello Adam

 

I am not sure how the archiver accepts the time zone offset in the ISO date time format, but yes you should account for the time zone by specifying UTC time stamps. For the DST this should be reflected in the time zone offset, the OS/application/etc. should reflect the DST change in the time zone offset when you read it. Assuming time zone offset is working, your time stamps looks correct. I think, from my experience, the best way to handle DST is just to read the current time and convert it to UTC assuming your OS is synchronized and you application/client/etc. is reading proper time zone offset.

 

Best Regards,

Abdalla

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> On Behalf Of Manoussakis, Adamandios via Tech-talk
Sent: Tuesday, November 15, 2022 1:07 AM
To: EPICS tech-talk <tech-talk at aps.anl.gov>
Subject: Epics Archiver Appliance requests and DST/Timezones

 

Hello,

 

I am trying to understand the best way to handle DST (and differing timezones as well) when requesting from the Archiver.  In the documentation I did find this one sentence “The times are in UTC; so any conversion to local time needs to happen at the client.” 

 

That leaves me with 2 questions, one about DST and one about time zones in general and requesting in matlab/python etc

 

1)      Does this mean then that when I do a URL request I need to account for what time zone the data was taken in?  Example I run the archiver in PST, data is stored at 1pm PST.  When I go to retrieve that data I need to put in the request 2012-012-27T01:00:00.000-800Z. If the data was taken in MST instead of PST then the URL would have to account for that and the it would now have to be 2012-012-27T01:00:00.000-700Z instead? 

2)      If the data was taken in DST same sort of question applies, I assumed the archiver handles DST but my request still has to account for the change.  Example data taken after March 13^th 1pm PDT the request would look like 2012-05-27T01:00:00.000-700Z and if it was outside DST request is 2012-012-27T01:00:00.000-800Z.

 

Just need clarification that the client doing the URL Request must add in the proper time zone where/when data is stored in Zulu  and DST.

 

Thanks,

Adam