We all know that the parliamentary elections will be held before June 2019. Apart from the Lok Sabha, elections will be held for the Vidhan Sabhas of Andhra Pradesh and Odisha.
The election dates have not been announced yet. But we can see what happened in 2014. The new Lok Sabha has to be convened at the latest within 5 years of its last constitution which was on June 6, 2014.
Counting of votes was on May 16, and Narendra Modi took office on May 26.
On March 3, the Election Commission announced the election schedule which was in 9 phases, starting from April 7 and ending on May 12. The election code of conduct came into force once this announcement was made.
This was the schedule in 2014:
Presumably the schedule in 2019 will not be greatly different.