I've partly got my RLS under control with a combination of medication (Ropinirole 2mg and pregabalin 25mg + 2 co-dydramal tablets) taken early evening. I also use a magnetic underlay on the bed.
Most evening the RLS kicks in between 19.00 and 11.00. And usually ends after 3 to 5 Hours, though occasionally it has gone on for 12 hours and sometimes kicked in during the day.
I don't know if is unusual to me but my RLS spreads up to my arms after several hours and ceases in my legs.
Also I've noticed it is usually worse I've been active, or been walking, cycling or swimming, during the day.
Another irritant for me while trying to sleep is I have sleep apnea, and have to use a CPAP machine. So if the RLS doesn't get me the sleep apnea usually does.