English of Core Text: Rabbi Shila said in the name of Rabbi: It is written “He made the moon for appointed times; the sun knows its setting” — from the fact that the sun knows its setting He made the moon for appointed times. And Rabbi Yochanan said: “And there was evening and there was morning, one day.”
On the daf / in context: The Yerushalmi discusses the determination of the new moon and the calendar. Rabbi Yochanan cites our phrase as a source for the primacy of the evening-morning unit.
Type of Learning: Custom (calendar / evening-morning unit)What Is Learned: The creation phrase supports the evening-to-morning definition of a day in calendrical matters.