Business Plan Timeline with regards to Start Date / Launch Date

I'm pretty sure I know whats the answer, would like another opinion.

I am using generic time values in my business plan (M1, Y1). I want to know the proper way of displaying my sales forecast. Should my sales forecast "start date" be from the product launch date, or the operations launch date. In other words, if there are number of months prior to launch with 0 sales, obviously I do not want to hide this but M1, Y1 after product launch could paint a different picture. The third option is to display an average for the first year but again is not showing 0 acceptable? What is the appropriate way to display my forecast.

Thank you.

In my dealings with Business Plans and proposals, I've found that investors and much appropriate audiences will still like to see that you realize you're not going to be generating revenue during development stages. The proverbial 'they' will look at this information and use it to evaluate whether they believe the development timeline is appropriate in regards to your market penetration/revenue generation once the production stage.

Simply put, show your cash flow for the entirety of the project. I usually do by month for the first 3 years, then by year for y4 and y5.