'Appointed Time' in the Bible

Let the children of Israel also keep the passover at its appointed time.

In the fourteenth day of this month, at evening, you shall keep it in its appointed time: according to all its rites, and according to all its ceremonies, shall you keep it.

And those men said unto him, We are defiled by the dead body of a man: why are we kept back, that we may not offer an offering of the LORD in its appointed time among the children of Israel?

But the man that is clean, and is not on a journey, and ceases to keep the passover, even the same soul shall be cut off from among his people: because he brought not the offering of the LORD in its appointed time, that man shall bear his sin.