iOS 日期加一天算法

 NSCalendar *calendar = [NSCalendar currentCalendar];

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

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

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

    NSDate *inputDate = [inputFormatter dateFromString:@"2013年01月31日"];

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

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