'Appointed Time' in the Bible

"The Israelis are to observe the Passover at its appointed time

on the fourteenth day of this month. You are to observe it at this appointed time between the evenings. You are to observe it according to all its decrees and laws."

and asked, "Why can't we bring an offering to the LORD at the appointed time among the Israelis, even though we are unclean because we came in contact with a corpse?"

Now as to the person who is clean and isn't traveling, but fails to observe the Passover, that person is to be eliminated from his people, because he didn't bring an offering to the LORD at its appointed time. That person is to bear his sin.

when you enter the land where you'll be living that I'm about to give you, you are to make an offering by fire to the LORD, either a burnt offering, a sacrificial offering to fulfill a vow, or a voluntary offering at the appointed time, to make a pleasing aroma to the LORD either from your cattle or from your flocks.

"You are to command the Israelis about my offerings that they are to be sure to bring edible offerings to me, presented by fire, and a pleasing aroma to me, at their appointed time.