Yeshua the Messiah is the Light of the world or the Sun of Righteousness (Mal 4:2) or the Greater Light to show man the path of spiritual darkness of this world. The saints are like the moon or lesser light that reflects the light of the sun or the greater light into the darkness of this world.
The biblical feasts are calculated based on the lunations of the moon. They YHVH’s plan of salvation to show man the way to Yeshua who is spiritually the Greater Light as represented by the sun. The feasts are like a tract or sermon by which the saints preach the gospel message of salvation to the world. The saints as the lesser light reflect the message of salvation through Yeshua the Greater Light into the darkness of this world through their adherence to the biblical feasts. This is why the moon — the lesser light — is so pivotal to YHVH’s calendar and feasts.
Judah’s calendar is off; it’s not in accordance with the moon. It claims to be, but it’s not. At the same time, they’re not bring the gospel message of Yeshua to the world — only the doctrines of men and men’s traditions. Their whole message is askew and fails to reflect the Greater Light of Yeshua.
Similarly, the mainstream church tries to preach the gospel, but without understanding the moon, feasts and biblical calendar their message of the gospel is only a partial one and is also off.
A time may come in the future when the calendar and feasts will go off the sun and not the moon. This may occur when there is a new heaven and a new earth when Yeshua is ruling on this earth and he will be the only Light of the world. That time isn’t yet, though, for it’s still the saints’ job as the lesser light to be like the moon to reflect the truth of Yeshua, the Greater Light, to this world through a lunar-based calendar and the biblical feasts.