Recruitment deadlines are strict and not to be missed. They also always arrive far more quickly than you expect. Please note the relatively short timespan between invitations to interview and the interview date itself (around 3 weeks only). Early preparation is crucial. Waiting for the invitation to interview before preparing is preparing to fail.
Application dates have not yet been released for August 2020 entry, but in the meantime here are the dates used for various stages of August 2019 entry. The timeframe is likely to be similar again.
The stages of application
Why is Anaesthetics so popular?