‘These are the feasts of YHWH, holy convocations which you shall proclaim at their appointed times.
(Lev 23:4 NKJV)

Passover

On the fourteenth day of the first month at twilight is YHWH’s Passover.
(Lev 23:5 NKJV+)

Days of Unleavened Bread

And on the fifteenth day of the same month is the Feast of Unleavened Bread to YHWH; seven days you must eat unleavened bread.  On the first day you shall have a holy convocation; you shall do no customary work on it.  But you shall offer an offering made by fire to YHWH for seven days.  The seventh day shall be a holy convocation; you shall do no customary work on it.’ ” And YHWH spoke to Moses, saying, “Speak to the children of Israel, and say to them: ‘When you come into the land which I give to you, and reap its harvest, then you shall bring a sheaf of the firstfruits of your harvest to the priest.  He shall wave the sheaf before YHWH, to be accepted on your behalf; on the day after the Sabbath the priest shall wave it. And you shall offer on that day, when you wave the sheaf, a male lamb of the first year, without blemish, as a burnt offering to YHWH. Its grain offering shall be two-tenths of an ephah of fine flour mixed with oil, an offering made by fire to YHWH, for a sweet aroma; and its drink offering shall be of wine, one-fourth of a hin.  You shall eat neither bread nor parched grain nor fresh grain until the same day that you have brought an offering to your Eloah; it shall be a statute forever throughout your generations in all your dwellings.
(Lev 23:6-14 NKJV+)

Pentecost

‘And you shall count for yourselves from the day after the Sabbath, from the day that you brought the sheaf of the wave offering: seven Sabbaths shall be completed.  Count fifty days to the day after the seventh Sabbath; then you shall offer a new grain offering to YHWH. You shall bring from your dwellings two wave loaves of two-tenths of an ephah.  They shall be of fine flour; they shall be baked with leaven.  They are the firstfruits to YHWH.  And you shall offer with the bread seven lambs of the first year, without blemish, one young bull, and two rams.  They shall be as a burnt offering to YHWH, with their grain offering and their drink offerings, an offering made by fire for a sweet aroma to YHWH.  Then you shall sacrifice one kid of the goats as a sin offering, and two male lambs of the first year as a sacrifice of a peace offering.  The priest shall wave them with the bread of the firstfruits as a wave offering before YHWH, with the two lambs. They shall be holy to YHWH for the priest.  And you shall proclaim on the same day that it is a holy convocation to you.  You shall do no customary work on it.  It shall be a statute forever in all your dwellings throughout your generations.  When you reap the harvest of your land, you shall not wholly reap the corners of your field when you reap, nor shall you gather any gleaning from your harvest.  You shall leave them for the poor and for the stranger: I am YHWH your Eloah.
(Lev 23:15-22 NKJV+)