During the initial 5-year period of 4MOST operations, 30% of the total available observing time will be available to the ESO community. It is currently  estimated that this fraction corresponds to 0.96 million fibre-hours per year for the low-resolution spectrographs, and 0.48 million fibre-hours per year for the high-resolution spectrograph. This is the time available for all Community Surveys, and it is not yet known how many Community Surveys will be selected. The allocation of time for individual Community Surveys will be guided by the principle of maximising the overall scientific output of 4MOST.