What is the schwa vowel sound in evening?

There is a schwa sound for the second E in one pronunciation, as in the Word even (eev-uhn).

The Word evening may have two different pronunciations: e-ven-ing and eve-ning.

In evening (making even), the first E is long, the second a schwa. In evening (night), the first E is long, the second silent, as in (eev-ning).