Any question answered...

One issue is that a conversation will often go like this:

Me- we can deliver this circuit in 65 working days
Client- so that's just over two months- awesome!
Me- Sorry, working days- that's around three and a half months

Later:

Client- the guy said they can have it installed in 6.5 days- so basically just over a week
Clients boss- place the order, start giving them biblical shit on day 7 if they have not got the circuit in by then- laywers, threats of violence, the whole thing

Have had that conversation before too. Brutal.

Always give them dates. "If you sign in October you will have it in December. If you keep delaying the contract you won't see it until after the Easter Bunny"