Find Earliest Date Changing by Slicer

I want to calcuate the first date of transmisson per each program.

Program | Tx Date

Spider Man | 26 Aug 2018

Avengers | 27 Jul 2018

Iron Man | 16 Feb 2018

Spider Man | 21 Aug 2018

Iron Man | 13 Feb 2018

Spider Man | 18 Aug 2018

The result will be

Program | Transmission Date

Spider Man | 18 Aug 2018

Avengers | 27 Jul 2018

Iron Man | 13 Feb 2018

I tried to use CALCULATE ( FIRSTNONBLANK(Transmission[Tx Date],1), ALLEXCEPT(Transmission, Transmission[Program]) ) but calculated value isn't changed when I change the date in Slicer. This calculated value is not dynamic and I want to create the earliest date changed when I move the slicer. Need your help to find out this dynamic value.