Is zakat obligatory on money paid to a real estate company to own an apartment, then retrieved before the completion of a hawl (a lunar year), or is the calculation of the hawl resumed from the date of retrieval?

If the dwelling is not precisely described in a way that prevents dispute, then the contract is one of gharar (definition) (excessive uncertainty) and is impermissible. In this case, the money has not left the possession of the questioner and its zakat (definition) must be paid when a hawl (lunar year) passes.

However, if the conditions for an istisna’ (manufacturing contract) are met and the dwelling is precisely described, then the contract is permissible. The money has left the possession of the questioner upon its payment to the company. If the money returns to his possession due to the annulment of the contract, then a new hawl begins for it.