Is it permissible to give a portion of Zakat before its due time, and will the Zakat due date for the coming year change accordingly? Is it permissible to give a portion of Zakat to a public hospital to purchase medical equipment or to distribute it among patients and staff? Is it permissible to pay off my husband's brother's loan to the bank and consider it from Zakat money, knowing that his salary is insufficient to cover his family's expenses?

It is permissible to advance some of the zakat (definition) before the completion of its year, and its original year does not change thereby. It is not permissible to pay zakat for purchasing equipment for a hospital because these do not fall under the eight categories specified by Allah in the Quran. However, paying zakat to hospital staff or patients is permissible if they are among the poor or the needy. It is not permissible to pay zakat to your sister's husband if he borrowed with usury, except after his repentance. But if his loan was good, you may pay zakat to him if he is poor.