Future dated sale deed

Admissibility of a document for want of stamp and registration is one thing, and the parties intending to take effect of  the Sale deed or Deed of Conveyance in future is another thing, as such there is no illegality in executing a sale deed in future date. If the document shows that contemplation of something being done in future by the vendor, the mere existence of such provision does not necessarily mean that the document is not a sale.

you can make deed of sale for future date 

The only difference between the Agreement to Sale and the Deed of Sale is completion of transaction. In case the entire money and the handing over of the possession have been simultaneously exchanged, the transaction is complete and the document is termed as Deed of Sale or Sale Deed.

However, if payment and possession is on a future date, the Agreement to Sale is entered. In Maharashtra, an Agreement to Sale coupled with future possession letter is recognised as complete sale without the requirement of any further document to be executed.