TimeZones at different points in time, have different offsets (e.g. January 1
and July 1 in L.A. -8 and -7 hours respectively).  

And they also, at different points in time, have different offsets for the
same point in time (e.g.
https://en.wikipedia.org/wiki/Time_in_Indiana#2006).


And their offset change arbitrarily without much notice
(e.g.https://www.washingtonpost.com/news/worldviews/wp/2016/07/06/egypt-cancelled-daylight-savings-time-three-days-before-it-was-due-to-start/)



Maybe a better approach for your use is to have a Time Zone cache so there
is only one canonical time zone for each time zone name/abbreviation combo
you're dealing with in your images.  






cbc wrote
> This change is requested after I couldn't get get TimeZone compares to
> work.  Try this before loading:
>   (TimeZone offset: (Duration hours: -7 minutes: 0) name: 'Pacific Time
> (US
> & Canada)' abbreviation: 'PDT')
>   =
>   (TimeZone offset: (Duration hours: -7 minutes: 0) name: 'Pacific Time
> (US
> & Canada)' abbreviation: 'PDT')
> 
> Returns false - since the hash isn't the same (different instances),
> although what they represent is exactly the same.
> 
> After this, returns true.
> 
> -cbc
> 
> On Thu, Sep 8, 2016 at 4:40 PM, <

> commits at .squeak

> > wrote:
> 
>> A new version of Chronology-Core was added to project The Inbox:
>> http://source.squeak.org/inbox/Chronology-Core-cbc.8.mcz
>>
>> ==================== Summary ====================
>>
>> Name: Chronology-Core-cbc.8
>> Author: cbc
>> Time: 8 September 2016, 4:39:41.903555 pm
>> UUID: 7315e61d-3652-fe44-8472-8037bd3ecc83
>> Ancestors: Chronology-Core-bf.7
>>
>> Add a rational #= to TimeZone - based on offset.
>>
>> =============== Diff against Chronology-Core-bf.7 ===============
>>
>> Item was added:
>> + ----- Method: TimeZone>>= (in category 'comparing') -----
>> + = aTimeZone
>> +       ^offset = aTimeZone offset!
>>
>>
>>





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