This is the 3901st most frequent German word.
tag
"Tag" (German) = "Day" (English)
Here, 'Tag' means 'day,' referring to the daytime period as opposed to night.
Heute ist ein wunderschöner Tag.
Today is a beautiful day.
In this context, 'Tag' is used in a greeting, symbolically representing the entirety of one's day.
Ich wünsche Ihnen einen guten Tag.
I wish you a good day.
Here, 'Tag' refers to the daytime hours, indicating the period of light rather than the entire 24-hour day.