NSDateFormatter still parsing instead having incorrect format

Question

Having some problems parsing date. I have an array of supported formats and once I receive the date (string) from API, I try to parse it iterating through the formats until

Answer 1

This could be related to the fact that NSDateFormatter will anyways respects the users settings when using fixed formats

Although in principle a format string specifies a fixed format, by default NSDateFormatter still takes the user’s preferences (including the locale setting) into account

So may be the locale defined in your preference uses '/' for separator and satisfies the 'incorrect format'. Even if that is not the case, apple noted in several places that NSDateFormatter might not act consistently. So try setting a fixed locale as below and see if that helps

NSLocale *locale = [[NSLocale alloc] 
    initWithLocaleIdentifier:@"en_US_POSIX"];
[dateFormatter setLocale:locale];

See these links for detail: apple tech note . Note directly related to separators, but that could be related.