A fully executed contract date begins once both parties signed it. In your case, since you signed them first, the date begins when the seller/affixes his signature. However, the delivery of the ratified contract should also be considered. Consult your realtor and a lawyer.
A group of spiders is called a cluster or clutter. Spiders belong to the group of animals called arachnids.
What is a group of animals called? Collective nouns are also called terms of venery. Go here to look up another animal. What is a group of goats called? Now you know what a group of gnats is called. Go here for the next animal on our list.