Just as with my Quick Hitter series on the FAR, my Quick Hitter series on the GSAR is meant to simplify contracting business with the government. This time with GSA.
GSAR 505.203 Publicizing And Response Time
This is in lieu of posting to FedBizOps which is now a part of the new SAM.gov. When advertising in a newspaper, you must give interested contractors three (3) days to draft a proposal in response to the contract project solicitation.
If advertising a real property contract under the TAA threshold, you must be given ten (10) days to respond with a proposal and for those over it’s forty (40) days.
I’ve talked to my friends in the Federal Government. Some acting and some retired. The rule of thumb on the response time of solicitation is usually ten (10) calendar days after the solicitation is posted. That being said, I’ve heard as low as one (1) calendar day and as much as much as one hundred and eighty (180) calendar days.
During my phone calls with clients, I routinely recommend that they prepare a shell proposal so that they are able to meet any required deadline as soon as possible.
If you think I can help you then email nicholas.s.robertson@outlook.com for your introductory email and free consultation. 
RobertsonKX Business Blog 