I think you should read letter properly first.

The letter mention ".... the payment of liquidated damages for the late delivery of the Vacant Possession (VP) pursuant to Clause 22 of the SPA shall be issued in favor of ________"

In SPA, the Clause 22 states that "If the vendor fails to deliver VP of the said bulding in manner stipulated in Clause 23 within time stipulated in subclause (1), the Vendor shall be liable to pay to the Purchaser liquidated damages calculated from day to day at the rate of 10% per annum of the purchase price from the expiry date of the delivery of VP in subclause (1) until the date the purchaser take VC of the said building......"

So I don't think they can simply decide funny T&C to cheat us.

Also, 31st July is just an indication, it might be earlier, or later. Doesn't matter when the VP will be, it will be taken into account to the liquidated damages payment.

Just my 2 cents