What do the following two-word phrases have in common that has nothing to do with their meanings?

1. Septic tank 

2. Apre ski

3. Jungle Jim

4. Novel approach

HINT:

It has to do with the beginning letters of each clue.

Answer:

 

The first three or four letters of each clue are the old-style abbreviations of the  30-day months:

(30 days hath September .......)

 Sept. - Apr. - Jun. - Nov. 

 

Credit:
Harvey Estes