On Eurovision.tv the schedule for rehearsals and press conferences has already been published, the first rehearsal will be on Sunday May 13th, when all the delegations have arrived to Baku, each rehearsal and press conference will last for 40 minutes, each day there will be 2 breaks, the first of an hour, and the second of 20 minutes.
Representatives of Montenegro, Island, Greece, Latvia, Albania, Romania, Switzerland, Belgium and Finland will attend first rehearsals from 11.00 to 20.15 on May 13.
Semifinalists will rehearse every day until May 19 and nine singers are expected to take the stage at the Baku Crystal hall during the rehearsals every day.
The Big 5 and the host country Azerbaijan will start rehearsals on May 19.
Main rehearsals will take place a day before the live show.
42 countries will attend the 57th Eurovision Song Contest in Baku. 18 countries will compete in each semifinal and 20 countries among them will be qualified for the finals. 26 countries will compete in the finals.
You can see the full schedule here.