Specific dates for the initial MATIC distribution have been estimated using the release schedule chart in the source material.
POL replaced MATIC in Sept 2023. The DefaultEmissionManager mints 2% annual inflation (compounded), split 50/50 between Validator Staking Rewards and the Community Treasury.
Staking Rewards section covers the pre-allocated 12% of initial supply distributed as MATIC staking rewards through Dec 2022.