Do both: trigger on t-60 mins with not sunny as a condition, and on t-30 mins. Assume it doesnโt matter if you try to turn the lights on when they already are?
You could do it either way: up to you. Playing around and finding what suits you best is part of the learning process. Two automations would be the simplest way: write the 30 mins one, copy it and alter the copy to 60 mins with the added condition.