In Outlook, you can schedule an event to recur on the 31st of the month - and it will (correctly?) presume you want the last day of the month for shorter months.
In Google, you can recur on the 31st, and it'll only happen on months with 31 days. 😒 Alter the recurrence logic via their API to be last day of the month (it's CalDAV's RRULE under the hood, and RRULE allows for this), and then it works - but then can't be edited via Google's interface. 😩
