As of August 2019, our Walt Disney World Room Finder tool sends room requests to Disney up to 30 days in advance of check-in. If your request is in our system and has both a name and a reservation number inputted more than 30 days before check-in, we will send it 30 days in advance. If you complete the request fewer than 30 days (and more than one day) prior to check-in, we will send the request the morning after your request is filled-out. Since they are unlikely to succeed on short notice, our system does not send requests created for same- or next-day check-ins.
If your request is sent but you later decide to change your Room Request, our system will submit another request on the next working day after you make changes (again, assuming that that the check-in date is between 2 and 30 days away). We do not know how Disney handles multiple requests for the same reservation, so you may want to explain your duplicate request in the "Additional Information" area of your latest request.
When your request has been sent, an alert appears on your dashboard. (The alert will generate an email if you have not clicked on the alert by the next morning.)
Note that prior to August 2019, we used a system that sent requests via fax about 5 days prior to check-in. That system is obsolete; at Disney's request, we moved to the current system with its 30-day-in-advance timeframe.