Work is ongoing and it will take as long as it takes to deploy reliably and securely. It is still expected to be UTC 15.03.2021 but no exact timeline will be available until it enters final validation.
We will try and give and update in the morning of 15.03 UTC if possible with information
This is a question for your individual exchanges, from the point they receive the XYM to the point of enabling trading will vary by exchange, I am not aware of any that have committed to a specific time at this point