Cut red dates into small pieces and soak in water for at least one hour, preferably overnight.
Transfer red dates with the soaking water into a pot. Add in longans. Cover the pot, bring to a boil and simmer for 25 minutes. Add in the goji berries and simmer for another 5 minutes.
Strain the tea. Add sugar (preferably dark brown sugar) if needed. Serve hot, warm, at room temperature or cold.
NOTES
Variation: Add one or two ginger slices in Step 2 and simmer together with the red dates and dried longans.
It's important to use seedless red dates to reduce the heatiness of the drink. Longans are also heaty, so use less or drink less of the tea if you are feeling heaty.