The Messenger of Allah ﷺ used to slaughter and sacrifice at the prayer ground.
كان رسول الله ﷺ يذبح، وينحر بالمصلى.
No references are available.
Bukhari reported it in the Book of Udhiya (5552) from Yahya bin Bukayr, who said, Layth narrated to us, from Kathir bin Farqad, from Nafi, that Ibn Umar informed him of it, and he related it as mentioned. Abu Dawud (2811) also reported it through another route from Nafi, with the wording that the Prophet ﷺ used to slaughter his udhiya at the prayer ground, and Ibn Umar used to do the same.The Eid prayer ground was in an open space outside the masjid, said to have been close to what is today Masjid Ghamama. This was specific to the Prophet ﷺ so that people could see him, since no one was permitted to offer his udhiya before the Prophet ﷺ did.As for offering the udhiya at night, there is nothing that prohibits it, and this is the view held by the majority of scholars of knowledge. However, the well-known position of Malik, and one narration from Ahmad, is that the udhiya is not permissible at night.I say, perhaps they said this because the night is a time of rest for the animal, just as it is a time of rest for a person.