We must remember that Yeshua (Jesus) taught by not only what he said, but by what he did.
Yeshua very clearly observed the Feasts of the LORD that are outlined in Leviticus 23. He went up to Jerusalem for Passover, Shavuot, and Sukkot. He performed miracles on the feast days.
And as his ministry concluded, he fulfilled the Spring Feasts through his death, resurrection, and the gift of the Holy Spirit.
Now, in order to keep the feasts, Yeshua had to be aware of the new moon sighting.