You will get an email notification approximately 24 hourrs ahead of when the event starts.
Around 1.9M (Mid of Feb,2018) , Musicoin will scheduled to fork. and that time apply EIP-155.
Around 1.7M (Mid of Jan,2018) or More earlier (End of Year) , Soft fork EIP-155.
Another Consideration with EIP-155 is enabling EIP-150 (Gas Fee change).