Erev Pesach: last time for eating chametz

(8) It is forbidden to eat chamets on the fourteenth of Nissan (Erev Pesach) from Halakhic midday (which is the beginning of the seventh hour of the day) and onward. And anyone that eats [it] at that time breaks a Torah prohibition, and is subject to lashes, based on Deuteronomy 16:3: "You shall not eat chamets upon it" - meaning to say, upon the Passover sacrifice. Based on the Gemara we learn: "You shall not eat chametz" from the time that is fit for the sacrifice of the Passover sacrifice, which is in "the afternoon" (Exodus 12:6) - and that is half the day.

(15) Any Torah verse that prohibits the eating of food, using expression such as: Do not eat, They may not eat, It must not be eaten, and so on, contains both an explicit prohibition of eating, and an implicit prohibition of deriving benefit, unless the verse gives explicit permission to derive benefit ... or unless the Oral Torah derives permission to benefit

Chametz from the sixth hour on the fourteenth is prohibited to benefit from, and the Sages prohibited (eating) it two hours prior to that. Nevertheless, from the start of the fifth hour and within that hour it is still permitted to benefit from it: for example, to sell it to gentiles .... You can also feed the leftover chametz to wild animals and birds, but only if you watch over them to make sure that they eat all of it. You must burn any leftovers. And from the start of the sixth hour and on the Sages also prohibited deriving benefit from it.