The provision of manna began on the fifteenth day of the second month after their departing out of the land of Egypt. It ceased on the seventeenth day of the first month forty years later.
Exodus 16:1 And they took their journey from Elim, and all the congregation of the children of Israel came unto the wilderness of Sin, which is between Elim and Sinai, on the fifteenth day of the second month after their departing out of the land of Egypt. 2 And the whole congregation of the children of Israel murmured against Moses and Aaron in the wilderness: 3 And the children of Israel said unto them, Would to God we had died by the hand of the LORD in the land of Egypt, when we sat by the flesh pots, and when we did eat bread to the full; for ye have brought us forth into this wilderness, to kill this whole assembly with hunger. 4 Then said the LORD unto Moses, Behold, I will rain bread from heaven for you; and the people shall go out and gather a certain rate every day, that I may prove them, whether they will walk in my law, or no.
Joshua 5:10 And the children of Israel encamped in Gilgal, and kept the passover on the fourteenth day of the month at even in the plains of Jericho. 11 And they did eat of the old corn of the land on the morrow after the passover, unleavened cakes, and parched corn in the selfsame day. 12 And the manna ceased on the morrow after they had eaten of the old corn of the land; neither had the children of Israel manna any more; but they did eat of the fruit of the land of Canaan that year.
Exodus 16:35 And the children of Israel did eat manna forty years, until they came to a land inhabited; they did eat manna, until they came unto the borders of the land of Canaan.
I cannot tell how many days because the months were lunar (29 or 30 days) and an adjustment was necessary to keep in step with the solar cycle.
I hope you find this helpful.