NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"eee, dd MMM yyyy HH:mm:ss ZZZ"];
NSDate *date=[dateFormatter dateFromString:{需要转化的字符串}];
NSDateFormatter *dateToStringFormatter=[[NSDateFormatter alloc] init];
[dateToStringFormatter setDateFormat:@"发布时间:yyyy-MM-dd HH:MM"];
NSString *nsDate=[dateToStringFormatter stringFromDate:date];