12 Miss. Code. R. 3-20-700.23
The Contractor must submit with each Application and Certification for Payment, or computer generated form, except Final Application for Payment, a separate letter stating an Extension of Time for that period of Time is or is not needed. No payment on a monthly application will be made until the letter is received. Complete justification such as weather reports or other pertinent correspondence must be included for each day's request for extension. A Contractor's letter or statement will not be considered as adequate justification. The receipt of this request and data by the Bureau will not be considered as the Bureau's approval in any way. When fifteen (15) days of lost construction time are accumulated, a change order must be prepared and, only upon the Bureau's approval, will the Time Extension be given.
12 Miss. Code. R. 3-20-700.23