Morning after Breakfast, proceed to Rohtang Pass up to snow line (point set by the govt. for safety). Enjoy the beautiful surroundings of Rohtang. The view from the place will take your breath away.
Or Solang Nala, which is one of the best place to be in Manali. It is situated at the top of Kullu Valley. Have fun & enjoy activities like paragliding etc. Later return to the hotel, dinner & overnight stay.