iOS 日历的bug

iOS 日历的bug ---- 2018.12.31 || 2018-12-31

{
//        date = [NSDate dateWithTimeInterval:i*24*60*60 sinceDate:date];
//        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
//        [formatter setDateStyle:NSDateFormatterFullStyle];
//        [formatter setTimeStyle:NSDateFormatterShortStyle];
//        [formatter setDateFormat:@"YYYY-MM-dd"];
//        NSString *dayString = [formatter stringFromDate:date];      
}

(lldb) po dayString
2018-12-31

意外发现哦！