Normally the Terumas ha'Deshen was done near Keri'as ha'Gever.

Yom Kipur it was done at Chatzos.

On Regalim it was done from the first Ashmorah, and the Azarah was completely full by Keri'as ha'Gever.

The Mishnah (in Zevachim) teaches that Chatzos is the cutoff to determine if Eivarim are considered consumed by the Mizbe'ach (and no longer subject to Me'ilah).

The source is a contradiction resolved by Rav to teach that the first half is for Haktarah; the second for Haramah.

Question: If, indeed, Chatzos is the cutoff d'Oreisa, then how could our Mishnah allow deviations from Chatzos?

Answer: R. Yochanan reinterprets the Pesukim and there are different times for different days.

Question: What is Keri'as ha'Gever?

Answer: It is a Machlokes between Rav (it means the caller) and R. Shila (it means the rooster).

The incident involves Rav serving as Meturgeman before R. Shila...

There is a Beraisa to support each definition:

In support of Rav, the Beraisa teaches that the caller summons the Kohanim, Levi'im, Yisre'elim...

Agripas rewarded him for his voice, heard at 3 Parsah.

The Kohen Gadol could be heard in Yericho, in spite of his weakness and it being daytime.

The noise of the sun blocks sounds during the day.

La is the name... as indicated by Nevuchadnezar.

Without the noise of the sun, Rome could be heard; without the noise of Rome, the sun could be heard.

Three voices travel throughout the world, the above and the Neshamah as it leaves the body (some add the sound at birth, others as Ridyah).

The Rabanan eliminated the cry of the Neshamah.

In support of R. Shila, the Beraisa speaks of the dangers of embarking before the cry of the rooster.