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.
The 35,000 known types of spiders are grouped into 70 different families. Some examples are tarantulas, which belong to the spider family Theraphosidae, and wolf spiders, which belong to the family Lycosidae.