Good observation. I had reserved online, on 3/31 and until this morning, it was showing 3/31 on mytesla page. Now, it is indeed showing 4/1/16.
Just wondering if this has something to do with the confirmation email date, which I received on Friday 4/1/16 (california time).
When did you get the confirmation email from Tesla? 3/31 or 4/1?