Escrow payment release duration

fsjani90

I am a supplier. My question has 2 parts.

1. Once we enter into a contract and goods are shipped and delivered. How much time is given to the buyer to release the payment? Can the time given to the buyer be reduced ?

2. In case we require a advance payment to be released prior to shipment. Would that be possible?

Please help me providing answers to my questions.
Thanks,
Jani