If the contract just read “on or before”, buyer still wins.

Whether a contract reads “on or before” or “no later than” or BOTH, time is NOT of the essence and the buyer, or seller, can still go beyond that deadline.

Yes, plain language is no assurance– remember we are dealing with lawyers, who have a language all their own.

But what is ambiguous about “No Later Than”

This is a great example of plane speak not working well.
I wonder what way it would have gone if the contract had just read
“on or before December 31, 2007″.

The buyer wins!

Case law, including from the Court of Appeals of NY (our highest court, see link below)is that contract language “on or before” or “no later than” does NOT make “time of the essence”, which is a legal term of art. If you want a client to do something by a certain date and suffer consequences, the best way is to set forth the consequences (eg: if you don’t close by December 31, all adjustments will nonetheless be calculated as if closing took place on December 31 (I use this one all the time when representing sellers) or if you want time to operate as a contract breach, with consequences being loss of downpayment and freedom to sell to another, you must use the actual term “TIME IS OF THE ESSENCE” (I prefer to use all caps as well).

http://www.nycourts.gov/reporter/3dseries/2006/2006_07520.htm

Related post:
The Secret of Contract Escape Clauses.

In my experience with this wording, the Seller would rarely have a case to win. The Contract allows flexibility with the closing date by saying “on or about”, and specifically doesn’t give a drop date unless written in by the Selling Agent. In this scenario though, the Buyer forfeited the “about” by going on vacation, IMO. Even though the time frame to close was broad, Buyer has every obligation to move the closing through as quickly as possible, so in this case I think Seller wins.

And the winner was … ?