You didn't have to start a new thread for this. A simple forum search for "same day oath" would have brought up several threads with it.
Same day oath is location-dependent. Some offices never have it, other places have it as a standard procedure if the application doesn't require waiting for supervisory review or follow-up documents from the applicant.
Note that if there is any arrest or conviction on your record, your application will automatically have supervisory review before it can be approved for the oath.