When Should Methadone Be Taken?

Good evening. I am 79 year old woman usually in excellent health. I have very aggressive restless leg syndrome that is resistant to any medications suggested by my Specialists or GP. I was until 18 months ago taking Dopergin (lisuride) which gave me good relief with occasional augmentation but it is no longer being manufactured. The recommended substitute Ropinirol had unacceptable side effects even though I persevered with it for 9 months and had to be abandoned and it never was entirely satisfactory. I have been taking methadone 2.5mgs daily for about 4 weeks and is helping somewhat. The symptoms are not as aggressive but still wake me 2 -4 times a night. My question is....what is the best time of the day to take it as currently I am very groggy up until mid afternoon. I am currently taking it at 6pm. I have also been taking Gabapentin for 12 months with no relief with the symptoms. I am currently weaning off it. The most I took was 2400mgms/ day and am now down to 600 mgms/day. I would really appreciate your help as I am usually energetic and busy. Raewyn