NSDateFormatter woes21 Feb 2011
NSDateFormatter has some really obscure behavior that I'm sure trips up a lot of people. A case in point. I have an app where a date is sent from the server in the format: "yyyy-MM-dd'T'HH:mm:ssZZ". You would expect that the following code would work just fine:
but you would be wrong. It appears that
- for certain locales (say Japan)
- when the phone is set to 12 hour mode
The date formatter ignores the date format and inserts its own localized AM/PM string and date string parsing fail. Now in Japan, the standard and thus majority of users use a 24 hour clock, so you will only get intermittent reports of errors/bugs which can be quite frustrating.
To fix this, instead of solely relying on setDateFormat, you need to set the locale. In a rather obscure Q&A, Apple recommends
I'm sure there are many apps, particularly ones developed with only an English speaking user in mind that contain this bug.