God called (or named): Naming something shows authority over it (see also 2:19–20).
day: The Hebrew word yom can mean:
daylight (1:5a),
a 24-hour period (1:5b), or
an unspecified time (2:4b, “when,” literally in the day; compare Exodus 20:8–11).
evening … morning: The Hebrew day started at sundown. This was like the first day that began with darkness and led to morning light.