Ibn Abbaas (radi Allahu anhu) said: “The Messenger of Allah (sal Allahu alaihi wa sallam) enjoined zakaat ul-fitr as a purification for the fasting person from idle and obscene speech, and to feed the poor. Whoever gives it before the (Eid) prayer, it is zakaat ul-fitr, and whoever gives it after the prayer, it is ordinary charity.”
[Sunan Abu Dawood - Classed as Hasan by Shaykh al-Albaani]
Zakaat ul-fitr must be given on behalf of all Muslims, young and old, male and female, free and slave. With regard to a foetus, it is not obligatory to give it on its behalf according to scholarly consensus, but it is mustahabb (recommended), because ‘Uthmaan (radi Allahu anhu) did that.
We benefit from the above report that it is also obligatory to give it before the Eid prayer, and it is not permissible to delay it until after the Eid prayer.
There is nothing wrong with giving it one or two days before the Eid. Hence it is known that the earliest time when it may be given, according to the more correct of the two scholarly views, is the night of the 28th of Ramadan, because the month may be twenty-nine or thirty days. The companions of the Messenger of Allah (sal Allahu alaihi wa sallam) used to give it one or two days before Eid.
We also benefit from the above report that those to whom Zakaat ul-Fitr must be given are the poor and needy.
As for what must be given as Zakaat ul-Fitr, we will inshAllah discuss it in tomorrows Hadith.
And Allah knows best!