Answer
Q: How long can a married person stay away from his wife?
A: A married person may stay away from his wife for whatever period that was
mutually agreed upon. However, if the wife is not happy regarding the
husband staying away, then the husband should meet his wife at least once
every four months. (Fataawa Nizamiya vol. 1 pg. 250)
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai