For most proposals, notification of at least 6-8 weeks in advance is expected. The actual science development of the project can take anywhere from 3 weeks (very rare) to 1 year or more, depending on the complexity of the project.

• If your project has any subcontracts, at least 6 weeks is strongly suggested. Subcontractors must have the signoff of their institution for their budgets and submission documents and many of those institutions require 2 weeks just to obtain all the signatures. They also need time to prepare the budgets and pull together all the paperwork associated with the application. 
• For NIH grants, if you expect that your grant proposal will be near or exceed $500,000 direct costs in any one year, you should notify us at least 10 weeks in advance so that we can prepare the budget.   Requests for permission of the funding institute to submit the grant is required 6-8 weeks before the deadline that permission must be received in writing.  Submissions will be completed through eRA Commons by the Grants Office.  Some agencies require a phone consultation with their scientific staff in addition to the letter.
• If you are preparing a program project grant or any very large multi-institutional proposals, you should allow between 3 and 12 (or more) months.