Boil pumpkin in reasonable amount of water as it will be needed to blend the pumpkin and pineapple then let both water and pumpkin cool.
In a blender, add pineapple, pumpkin (with water) and ginger; blend on high speed until everything is well blended together. Add sugar, Stir well until sugar is dissolved. Taste, and if not sweet to your suit, add sugar to your desired sweetness along with lime juice.
Strain juice through a fine-mesh sieve. Serve immediately, Before serving add a few ice cubes to the glasses put to chill if you prefer a colder beverage.