I would print them out, address them and take to post office first thing in morning.  Maybe a kind clerk will roll back date and mark them as 3/15.  Or put in overnight box with a time stamped photo of you putting them into box at 11:30.  Phones can be programed for different time zones. Then just argue with IRS that you did have them in if notice appears.

I myself know a postmaster and another employee with inside access who will back date an envelope on occasion if it is only few hours late.  Maybe you have friend in post office.

Of course if the IRS is monitoring this site, my name is IRMN and I do taxes in the iron range up in MN.