Every month, usually with a deadline of the 20th to the 25th of the month, you need to freeze the forecast for the coming month or months. That means that by the 25th of the current month you need to take an extra good look at the Live forecast for the coming months, and make any adjustments needed before going to the Tools menu and selecting Submit Live forecast as the Forecast for the next month. Once this has been submitted, it should not be changed once you enter that month. 

You can choose to submit an individual month or several months at once.