This sounds so sad in any language
It is sunday today and this comment really made me laugh, thank you.
How can we know if it is tomorrow or yesterday?
It depends on the tense. If it is future (or present, like here), it means tomorrow. If it is past, then it means yesterday.
@MarcinM85 meant that ''है'' indicates that the tense is present.
yes, so if this works like in english, then it's "tomorrow". tomorrow IS (present, not future, mind you), but yesterday WAS (necessarily past, never present)
था would indicate past tense