ios – NSDateFormatter不为“z”或“zzz”说明符显示“Asia / Kolkata”的时区缩写,只显示GMT偏移量

在iOS5模拟器和设备上,NSDateFormatter不为“z”或“zzz”说明符显示“Asia / Kolkata”的时区缩写.

NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:@"Asia/Kolkata"];
NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
dateFormatter.dateFormat = @"z"; // or @"zzz"
dateFormatter.timeZone = timeZone;

NSLog(@"date String: %@",[dateFormatter StringFromDate:[NSDate date]]); // "GMT+05:30",expected "IST"
NSLog(@"time zone abbreviation: %@",[timeZone abbreviationForDate:[NSDate date]]); // "IST"

我希望上面的代码输出：

IST
IST

但它输出：

GMT+05:30
IST

编辑

将语言环境设置为印度语语言环境似乎没有帮助.

NSLocale *indianEnglishLocale = [[[NSLocale alloc] initWithLocalEIDentifier:@"en_IN"] autorelease];
NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:@"Asia/Kolkata"];
NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter setLocale:indianEnglishLocale];
[dateFormatter setDateFormat:@"z"]; // or @"zzz"
[dateFormatter setTimeZone:timeZone];

NSLog(@"date String: %@",[timeZone abbreviationForDate:[NSDate date]]); // "IST"

我希望上面的代码输出：

IST
IST

但它输出：

GMT+05:30
IST

这是一个错误吗？难道我做错了什么？ People have mentioned that NSDateFormatter has bugs,especially when a time zone is specified in the format string. Could this be one of those bugs?

NSLocale *indianEnglishLocale = [[[NSLocale alloc] initWithLocalEIDentifier:@"en_IN"] autorelease];
NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:@"Asia/Kolkata"];
NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter setLocale:indianEnglishLocale];
[dateFormatter setDateFormat:@"V"];
[dateFormatter setTimeZone:timeZone];

NSLog(@"V date String: %@",[dateFormatter StringFromDate:[NSDate date]]);

V date String: IST