iPhone：NSDate的轉換GMT爲本地時間

Question

我現在有一個API調用返回我的日期/時間格式爲：2010-10-10T07:54:01.878926

我可以假設這是GMT？我也將其轉換爲一個NSDate對象。有沒有辦法使用本地iPhone時間重新計算時間？

Answer 1

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; 
dateFormatter.dateFormat = @"yyyy-MM-dd'T'HH:mm"; 

NSTimeZone *gmt = [NSTimeZone timeZoneWithAbbreviation:@"GMT"]; 
[dateFormatter setTimeZone:gmt]; 
NSString *timeStamp = [dateFormatter stringFromDate:[NSDate date]]; 
[dateFormatter release]; 

Answer 2

NSDate *sourceDate = [NSDate dateWithTimeIntervalSince1970:gmtTimestamp]; 
NSTimeZone* destinationTimeZone = [NSTimeZone systemTimeZone]; 
NSInteger sourceGMTOffset = [destinationTimeZone secondsFromGMTForDate:0]; 
NSInteger destinationGMTOffset = [destinationTimeZone secondsFromGMTForDate:sourceDate]; 
NSTimeInterval interval = destinationGMTOffset - sourceGMTOffset; 
NSDate* destinationDate = [[[NSDate alloc] initWithTimeInterval:interval sinceDate:sourceDate] autorelease]; 
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; 
dateFormatter.dateFormat = @"yyyy-MM-dd'T'HH:mm"; 
[dateFormatter setTimeZone:destinationTimeZone]; 
NSString *localTimeString = [dateFormatter stringFromDate:destinationDate]; 

Answer 3

NSDate *now = [NSDate date]; 
NSLog(@"%@", [now dateWithCalendarFormat:@"%Y-%m-%d %H:%M:%S" 
       timeZone:[NSTimeZone timeZoneWithName:@"GMT"]]); 

Answer 4

NSDate* localDateTime = [NSDate dateWithTimeInterval:[[NSTimeZone systemTimeZone] secondsFromGMT] sinceDate:pubDate];