Note: If you don’t have an account with unused invitations, you'll need to log in as an admin and go to https://test.archiveofourown.org/users/USERNAME/invitations to grant some.
Log in to an account with unused invitations
Hi, username! > My Dashboard > Invitations
Choose an invitation and enter an email address
Make note of either the email or invitation token (the keysmash)
Press "Send Invitation"
Follow the "Manage Invitations" link
Locate the invitation you just sent
Follow the linked token (the keysmash)
"Sent at" has no information below it.
"Sent at" should have a time and date below it, just like "Created at" does.
However, it appears the last time we successfully recorded this was back in 2012 (some data removed):