Hi por, I think the spring is the best time with the autumn a close second.
If you can get a nice early start in the spring, hopefully it will start to get established before the summer comes when drying out can be a real problem. Good luck Tbird+
around may/june is the best time, as the weather needs to be mild but clear, this way you can allow the turf to root properly before summer sets in, always water you fresh turf regurlarly to prevent it from dieing off.