获取AM/PM时间格式值的代码

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US"]];
[formatter setDateFormat:@"HH:mm:a"];
NSString *ampm = [[[formatter1 stringFromDate:[NSDate date]] componentsSeparatedByString:@":"] objectAtIndex:2];

ampm得到的值@"AM"就是了

//下面是在指定日期上加上任意天数

 NSCalendar *calendar = [NSCalendar currentCalendar];

      NSDateFormatter *inputFormatter = [[NSDateFormatter alloc] init];

      [inputFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier :@"zh_CN"]];

      [inputFormatter setDateFormat:@"yyyy年MM月dd日"];

      NSDate *inputDate = [inputFormatter dateFromString:@"2014年07月23日"];

      NSDate *nextDate = [NSDate dateWithTimeInterval:24*60*60 sinceDate:inputDate];

      NSDateComponents *comps = [calendar components:NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitWeekday|NSCalendarUnitDay fromDate:nextDate];