Why can we start entering 2023 data from November 2023 if the FEM calls for reporting data from the entire calendar year? If we start in November, two months will be missing.

Indeed, the full calendar year's data will need to be included. According to the standard FEM timeline, the cadence opens in early November, but posting FEM modules is not possible until January 2024. It is to the user's discretion as to when they may wish to purchase, start and verify the FEM which is possible at any time while the cadence is live, from early November to late October of the next year.