It once happened that [Rabban Gamaliel’s] sons came from a house of feasting.
They said to [Rabban Gamaliel]: "We have not recited the Shema."
He said to them: "If dawn has not broken, you are obligated to recite it."
“[This is true] not only in this case; rather, in all cases where the Sages said that [some precept can be performed only] until midnight — the precept is [still in force] until the break of dawn.
“[For example:] Burning the fats and organs [of the sacrifices, on the Temple altar] — this precept [can be performed] until the break of dawn.