Negotiation timeline question

[Amanda G.]

Hi All,

I put in an offer on a duplex. The response from the seller's agent came in as a text at 5:29 pm last night when the offer was set to expire at 5:30. The seller counter offered, and I counter-counter offered yesterday evening. The agent said she would tell them my counter.

What is a usual amount of time I should expect before receiving an answer?
How long is the offer considered still in effect?

Thanks!