Hilchos Maasei Hakarbanos 1:13

Consecrated animals are counted hour to hour, meaning that if they’re an hour too old or an hour too young, they’re unfit for the altar. For example, if an offering must be under a year old and it’s a year plus one hour, it’s unfit. This is so even if the animal was exactly a year old when it was slaughtered and more time passed until its blood was sprinkled on the altar. It must be within a year until the time the blood has been sprinkled. The same is true with any kind of offering.

Hilchos Maasei Hakarbanos 1:14

Whenever the Torah says “a male sheep” (keves), “a female sheep” or “sheep” (plual), it means in its first year. “A ram” (ayil) or “rams” means a male in its second year. It becomes a ram 31 days into its second year. On day 30, however, it may not be offered as a sheep or a ram. Such an animal is called “pilgas” [arguably meaning “tween” – no longer a child but not yet an adult]. When the Torah says “a calf” (eigel), it means in the animal’s first year. “Bull” (par) means in its second year. “A kid of goats” (se’ir izzim) is until its second year, while it’s “a goat” (eiz) its entire second year [from the very beginning, unlike a sheep].