Hardwood Installation/Acclimation Question
Longer the better with solid products, especially with that unpredictable critter..maple. Engineered? Some manufacturers say it's not important but they've been wrong before.
Florida Wood Floors.Net
A time frame is not so important as the moisture content. There are moisture meters that test for moisture content. 6 to 8 percent moisture is good. You also need to check the moisture content of the subfloor.
Depending on where the wood has been stored prior to delivery to your house and the weather when it was delivered can affect the time frame. Moisture content is the factor you need to watch. Never have wood delivered when it is raining or snowing. It will pick up moisture.
If your wood is coming from a lumber yard that stores the wood outside you may need to wait longer for the moisture content to be right than wood that comes from a box store that has the wood inside the store in a controlled environment.