Take mango powder, 1 cup water and finely crushed jaggery in a wok or pan and place it in low flame for heating.Meanwhile cut dates in thin slices.When the jaggery dissolved in water completely, add following spices to it – black salt, garam masala, ginger powder, red chilly powder and stir well.Let it simmer for 5 minutes and then add chopped dates to it and cook for another 5 to 6 minutes.Chutney is now ready, turn of the flame and transfer it to another bowl.Let the chutney cool down and then store in any air tight container. It keeps good for up to 6 months. Serve this delectable sweet-tangy chutney with any dish and relish eating.