iOS日期转换之UTC/GMT时间格式

//将本地日期字符串转为UTC日期字符串
//本地日期格式:2013-08-03 12:53:51
//可自行指定输入输出格式
-(NSString *)getUTCFormateLocalDate:(NSString *)localDate
{
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    //输入格式
    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    
    NSDate *dateFormatted = [dateFormatter dateFromString:localDate];
    NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:@"UTC"];
    [dateFormatter setTimeZone:timeZone];
    //输出格式
    [dateFormatter setDateFormat:@"yyyy-MM-dd‘T‘HH:mm:ssZ"];
    NSString *dateString = [dateFormatter stringFromDate:dateFormatted];
    [dateFormatter release];
    return dateString;
}

//将UTC日期字符串转为本地时间字符串
//输入的UTC日期格式2013-08-03T04:53:51+0000
-(NSString *)getLocalDateFormateUTCDate:(NSString *)utcDate
{
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    //输入格式
    [dateFormatter setDateFormat:@"yyyy-MM-dd‘T‘HH:mm:ssZ"];
    NSTimeZone *localTimeZone = [NSTimeZone localTimeZone];
    [dateFormatter setTimeZone:localTimeZone];
    
    NSDate *dateFormatted = [dateFormatter dateFromString:utcDate];
    //输出格式
    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString *dateString = [dateFormatter stringFromDate:dateFormatted];
    [dateFormatter release];
    return dateString;
}