Well, it's my understanding that an "aura" is a simple partial (usually), and they often go on for some time. They certainly seem to do with our Jonathan -- he's nonverbal, so he can't tell us what's going on, but he will often get very restless and fearful, his eyes will get dilated, and he'll and show certain behaviors like his hand shaking and so forth...and about 50% of the time that behavior leads right into a tonic seizure. This can last for a few minutes, or for an hour or longer. Sometimes we can get him calmed down, and head off a tonic or tonic/clonic by removing stimulation in his environment (drawing shades, turning off TV or music, dimming lights) or holding him on the bed til he falls asleep, but that doesn't always work. Other times he'll have a seizure very suddenly, with no warning.
Jon has also had gelastic (laughing) seizures that lasted for hours (I think this is a type of simple partial) and then they usually end with a "real" seizure (tonic or tonic/clonic). Almost the entire school day, one time (we didn't know that it was a seizure at the time, but it certainly concerned his teacher).
Tonic and tonic-clonic seizures are usually brief (if they aren't, you're in big trouble), but I believe other seizure types and auras can last for a long time. There's something called "NCSE" -- or non-convulsive status epileptus, where you can be in a seizure for hours or days, but without convulsions --
http://professionals.epilepsy.com/page/e_b_nonconvulsive_status_epilepticus.html
"characterized by confusion or diminished responsiveness, with occasional blinking or twitching, lasting hours to days"
"fluctuating lack of responsiveness or confusion"
"One of the most interesting is a disturbance of language (without confusion or stupor) termed aphasic status epilepticus. This can appear quite similar to the new-onset aphasia from a stroke"
Have you had an EEG done when you were having one of these episodes? If it is a seizure, an EEG will show abnormalities while you are having the episode (unless it's originating too deep in the brain, like in the hypothalamus, which often is the case with gelastic seizures).
This describles some of the symptoms of simple partial seizures -- which can vary from person to person, depending on the part of the brain affected:
http://www.epilepsyfoundation.org/aboutepilepsy/seizures/partialseizures/simplepartial/index.cfm