#888 days from the elevator 11/22/2018

If you don't count the 1st day Trump rode down the elvator and count from his 1st full day on the campaign trail 6/17/2016 it will be 888 days on 11/22/2018 
From and including: Friday, June 17, 2016
To, but not including Thursday, November 22, 2018
Result: 888 days 

888 days from prince's death... 
Your starting date is April 21, 2016 so that means that 888 days later would be September 26, 2018.

From and including: Thursday, April 21, 2016
To, but not including Thursday, November 22, 2018
Result: 945 days

135 weeks