Timing of seizures

My 16 year old son had several seizures when he was 6 - 8 years old. He discontinued medication when he was 11 years old. Five months ago he began having seizures. After videotaping and having a sleep deprived EEG, it was determined he was having focal (partial complex) seizures with secondary generalization. I have rescue meds for him and am instructed to give them for a seizure lasting longer than 3-5 minutes. My question is timing the seizure. Do I start timing when I notice he is starting to have a focal seizure or just time the tonic clonic portion? If I start when he begins the focal seizure (usually starts to look like a hot flash, then lip smacking and involuntary eye movement) his seizures are generally over 12 minutes. The tonic clonic portion is generally under 5 minutes. Before we had rescue meds, we did call 911 several times and the ER seemed annoyed that we were there. He also has autism and isn't a fan of ERs. Thanks!