NSDate 时间戳与字符串转换

一，转化的方法为
    NSString *timeSp = [NSString stringWithFormat:@"%d", (long)[localeDate timeIntervalSince1970]];
    NSLog(@"timeSp:%@",timeSp); //时间戳的值

二，把获取的时间转化为当前时间
 NSDate *datenow = [NSDate date];//现在时间,你可以输出来看下是什么格式
    NSTimeZone *zone = [NSTimeZone systemTimeZone];
    NSInteger interval = [zone secondsFromGMTForDate:datenow];
    NSDate *localeDate = [datenow  dateByAddingTimeInterval: interval];
    NSLog(@"%@", localeDate);

3.把时间戳转化为时间的方法
    NSDate *confromTimesp = [NSDate dateWithTimeIntervalSince1970:1363948516];
    NSLog(@"1363948516  = %@",confromTimesp);

//timer
    NSDate *datenow = [NSDate date];//现在时间,你可以输出来看下是什么格式
    NSTimeZone *zone = [NSTimeZone systemTimeZone];
    NSInteger interval = [zone secondsFromGMTForDate:datenow];
    NSDate *localeDate = [datenow  dateByAddingTimeInterval: interval];
    NSLog(@"%@", localeDate);

    NSString *timeSp = [NSString stringWithFormat:@"%lld", (long long)[localeDate timeIntervalSince1970]];
    NSLog(@"timeSp:%@",timeSp); //时间戳的值 1369189763711   1369218563 1369218614

    NSDate *confromTimesp = [NSDate dateWithTimeIntervalSince1970:1369189763711/1000];
    NSLog(@"1363948516  = %@",confromTimesp);

    //实例化一个NSDateFormatter对象

    //判断昨天 前几天等 判断今天凌晨时间戳
    NSDateFormatter *dateFormatter1 = [[[NSDateFormatter alloc] init] autorelease];
    [dateFormatter1 setDateFormat:@"yyyy-MM-dd 00:00:00"];
    NSString *currentDateStr1 = [dateFormatter1 stringFromDate:[NSDate date]];
    NSLog(@"凌晨时间:%@",currentDateStr1);
    NSString *timeSp1 = [NSString stringWithFormat:@"%lld", (long long)[localeDate timeIntervalSince1970]];
    NSLog(@"凌晨时间戳:%@",timeSp1);
    //昨天凌晨时间戳
    NSString *timeSp2 = [NSString stringWithFormat:@"%lld", (long long)[localeDate timeIntervalSince1970]-24*60*60];
    NSLog(@"昨天凌晨时间戳:%@",timeSp2);