The start time should be automatically adjusted to your timezone, but it starts at 4:00 PM EST.
You can convert that to double-check, or add the remaining time left on the countdown to your local time as well.
I played it a couple of times and in the first instance, the stamp went a bit crazy. I think I pushed it too far into the collider below it because it stamped several times in a second. But, did nothing. When I tried it again, it worked for the first sheet of paper, but not the second. So, I'm not exactly sure what was happening.
For transparency for others that may see this, the Moderation Logs for the jam says that the "Owner removed their own project." But don't worry, we'll get the game re-added.
Edit: I sent a friend request to the OctoXR account on Discord. I can then provide a link to get the game added back into the jam.