Woods dont need years to dry out,they are kiln dried.Hardwoods tend to take a lot longer because of the density of the timber in question,all hard woods are different as well.By Kiln drying Timber it refers to the concentration of RESIN within the wood the denser the wood the longer it has to spend in the kiln in what we called to "Dry" the Timber.We do this by weighing the Wood then in the kiln which opperate by steam and fans and periodically test the timber with moisture meters and again weighing the Timber til it reaches a certain point of dryness.A couple of examples Mohagany takes longer usualy to dry than Hard Maple as its a more denser timber.
Bottom line is ?"How do i know this about timber",well i worked in the Timber industry for 25 years manufacturing hardwood and softwood flush firedoors.
Roasted maple takes on average a month to dry the resin tops.