When the Torah says simply "and God called the light Day, and the darkness He called Night," Targum Pseudo-Jonathan on (Genesis 1:5) pauses to explain why. Naming, in the Targum, is not decoration. It is purpose.
The Lord called the light Day, the Targumist writes, "and He made it that the inhabiters of the world might labour by it." Darkness became Night, "that in it the creatures might have rest." The cosmos is sorted into work and rest before there is anyone to work or rest. The scaffolding of Shabbat is already being laid on the first day.
This is a quietly radical reading. Pseudo-Jonathan turns the first act of division — light from darkness — into the first labor law. Every creature that will ever exist already has a right to rest written into the fabric of the first day. Work is holy because it ends. That is why the evening comes before the morning in Jewish reckoning: rest is not recovery from labor, it is what labor is for.