Just got an email, a few minutes ago saying

Thank you for using the FINAL FANTASY XIV Mog Station.
This e-mail has been sent to inform you that additional game time has been added to the following service account after the first character on the service account reached level 30:

Service Account Name: <redacted>
Additional play time granted: 15
Date added: 01/31/2022
So it's about 5 days? Or maybe done on the last of the month.

Not sure what the 31st month is? Hmmm. trigintaunus-er maybe.