Aruch HaShulchan, The Laws of Tzedakah, 256:15

All who dwell in the city are obligated to give to all city tzedakah funds, and such the sages said (Baba Batra 8a) that “whoever dwells in the city for thirty days can be forced to give tzedakah to the public fund along with the rest of the community. If a person dwelled there for three months they can force that person to give to the food collective. If a person lived there for six months they can force that person to give to the clothing fund so that they can clothe the poor of the city with it. If a person dwelled there for nine months they can force that person to give tzedakah to the burial fund so they can bury the poor and cover all burial needs with it. [Translation by Rabbi Bruce Elder. Edited for gender neutrality]