Replacing Zakaat Funds With Sadaqatul Fitr Funds

An organisation collects Sadaqatul Fitr from the brothers of the community. It then buys groceries and prepares Sadaqatul Fitr hampers for the poor Muslims of the community. These hampers are prepared during Ramadhaan and are handed out a few days before Eid.

Many brothers only give their Sadaqatul Fitr money towards the ending of Ramadhaan or on Eid day before the Eid Salaah. This is collected by the Imaam of the community.

The organisation when buying groceries for the Sadaqatul Fitr hampers considers these extra funds that will be handed in late (although the exact amount is not known) so they purchase groceries for more than the amount they have already collected. The extra amount of money is taken from the Zakaat Account of the organisation.

When the extra Sadaqatul Fitr monies are given, they deposit this money into the Zakaat account to make up for the deficit.

For example:

Sadaqatul Fitr Funds collected till 20 Ramadhaan: R10 000

Groceries purchased: worth R20 000 (R10k of Sadaqatul Fitr and R10k from Zakaat Account)

Sadaqatul Fitr collected from 21 Ramadhaan to Eid morning: R10 000. This R10k is deposited into the Zakaat Account.

1. Is it correct to do this? To use Zakaat funds for poor Muslims and then replace it with Sadaqatul Fitr funds?

2. If the Sadaqatul Fitr collected at the end amounts to more than the deficit, for example R15k, then what should be done with the extra amount?

3. Does Sadaqatul Fitr have to be handed out to poor Muslims (either in cash or kind) during Ramadhaan or on Eid day, or can the funds be stored and used at a later stage to give to poor Muslims?