How is justice achieved between wives when it comes to going out for necessities like shopping, hospital visits, and family visits, when the husband is compelled to go out with one of them on a day that is not hers?

The justice obligatory upon the husband pertains to the nighttime stay (mabit), and it is not permissible for the husband to enter upon a wife who is not due for her turn during the day, except out of necessity. Examples of such necessity include the wife needing financial support (nafaqah) or her illness. If the wife needs to go to the hospital or the market, there is no blame upon the husband for accompanying her, even if it is not her turn. The criterion for determining necessity is common custom (urf).