Sharepoint Unique values over 3 columns

Good Morning,

I am trying to find a solution, I have a list which i need to make unique value over 3 columns

1st Column - Reservation Date - (DATE&TIME)

2nd Column - Time Slots (CHOICE)

3rd Column - Resident Full Name ( Look Up Value)

would like to make these all column together as unique so i wont make "double" reservation.

Appreciate if i get some help with this.

Thanks