时间戳与日期的相互转换

//日期转换为时间戳 (日期转换为秒数)
    NSDate *date = [NSDate date];
    NSLog(@"当前日期为(0时区):%@",date);
    NSDateFormatter *dateFormetter = [[NSDateFormatter alloc] init];
    [dateFormetter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString *timeStr = [dateFormetter stringFromDate:date];
    NSLog(@"timeStr（当前时区） = %@",timeStr);
    NSTimeInterval timeStamp= [date timeIntervalSince1970];
    NSLog(@"日期转换为时间戳 %@ = %f", date, timeStamp);

//时间戳转日期 (秒数转日期)
    NSString *timeStamp2 = @"1449732239";
    long long int date1 = (long long int)[timeStamp2 intValue];
    NSDate *date2 = [NSDate dateWithTimeIntervalSince1970:date1];
    NSLog(@"时间戳转日期 %@  = (0时区)%@", timeStamp2, date2);
    NSDateFormatter *dateFormetter1 = [[NSDateFormatter alloc] init];
    [dateFormetter1 setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString *timeStr1 = [dateFormetter1 stringFromDate:date2];
    NSLog(@"当前时区timeStr = (8时区当前时区)%@", timeStr1);

时间戳与日期的相互转换

原文：http://www.cnblogs.com/songtingting/p/5050940.html