Dear Vivian we use Kal in both ways as yesterday and also as tomorrow . So depending on the tense we translate it . For example "Kal me bazaar gaya tha."In this case it means I went to the market yesterday (This was in simple past tense ) . But if I change this sentence "Mujhe kal bazaar jana hai ." It becomes I need to go to the market . So there is a difference between the use of the word .