Timing will usually differ from person to person depending on the amount needed. I take mine at 7am, 1pm and 8pm I may need to add an extra dose at some point to get me through the nights, but I also take sleep aids and so far so good.
Old+Slow - You must not be too advanced in PD. My mom takes hers at 5:30 am, 1pm and 8PM but really she's depleted after about 6 hours each time. I can't give her another dose because the dyskinesia sets in. She is at her limit.