Is it permissible to make the intention that any amount given to the poor and needy is Zakāt, and whatever exceeds it is Sadaqah, or is it permissible to give daily or weekly amounts with the intention of Zakāt before its due date?

One should not exceed the obligatory amount in Zakat with the intention that the excess is part of the obligatory Zakat, as this may lead to an alteration of the divinely prescribed measures. Exceeding the divinely set limit is a reprehensible innovation (bid‘ah makruhah). However, if the increase is separate from the obligation, then it is a voluntary act (nafl). Therefore, it is preferable not to intend the increase as an obligation. One can give voluntary charity (sadaqah tatawwu‘) and Allah will reward it, just as it is permissible to pay the obligatory Zakat before its due time.