I am trying to create and auction on my mac computer

So I plug in:

05/11/2020

to

05/15/2020

I get an error thing.

Jeri says try tommow as the start day

So I plug in this:

05/12/2020

to

05/16/2020

And I get this thing:

-

Warning: checkdate() expects parameter 1 to be long, string given in /home/horseede/public_html/hostauction.php on line 207

Warning: checkdate() expects parameter 1 to be long, string given in /home/horseede/public_html/hostauction.php on line 218

Maybe I'm doing something wrong but someone else had this issue and does auctions on their phone. Let me know please!

This is happening to me too! Doing it on my phone works for some reason though.