According to a narration from Salman Ibn Amir, the Messenger of Allah said:
“When any of you wants to make iftar, let him have date. If there is no date, let him have water. Water is clean.” (Abu Dawud, Fast 21; Tirmidhi, Tax 26, Fast 10; Ibn Majah, Fast 25)
Anas Ibn Malik said: “The Messenger of Allah used to make iftar with a few pieces of persimmon before the evening prayer. If there is no persimmon, he used to eat date. If there is no date, he used to drink a little water.” (Abu Dawud, Fast 21; Tirmidhi, Fast 10)
The important point is that making iftar with persimmon or date is not a must. It is only an advice for the ones who try to do just like the Messenger did.