NSDateFormatter for BST instead of GMT+1

Question

I want to display the following string on my time axis:

\"GMT/BST\"

Here\'s the code:

 NSDateFormatter *dateformatter=[[NSDateFormatter alloc         


        

Answer 1

I spent a day on this and wanted to make sure so others don't get hung up on it.

For a UK region/locale, the 'z' field pattern in DateFormatter returns the proper string for the "America/London" timezone (e.g. "GMT" or "BST"). However, if you use the US region/locale, 'z' will give you "GMT+1".

The gotcha happens when an abbreviation for the given target timezone with a given locale doesn't exist. I was using the 'v' field pattern, and with the US region, "Europe/London" was falling back to "United Kingdom Time", which blew up my text label. 'z' is better, it falls back to "GMT+1" while in DST, but still not the desired "BST".

The abbreviationDictionary doesn't consider daylight savings time. It's meant to map an abbreviation to a timezone. You'll find "BST":"Americal/London", but this only applies while observing daylight savings time as mentioned by @Nick T. During standard time, Brits are used to seeing "GMT".

Unfortunately, without recreating timezone functionality yourself, you're left with compromises. I think iOS can do better here.

Reference

• Date Field Symbol Table as part of the Unicode Technical Standard