Day-and-night and In full swing

Day-and-night adjective - At all times.

In full swing and day-and-night are semantically related. In some cases you can use "In full swing" instead an adjective phrase "Day-and-night".

In full swing adverb - Proceeding with full vigor.

Day-and-night and in full swing are semantically related. Sometimes you can use "Day-and-night" instead an adjective phrase "In full swing".