Wife dedicating her time to the co-wife

It is permissible for a woman to give up her night to her co-wife or to her husband as this is her right. It was authentically reported that the mother of believers Sawdah (may Allah be pleased with her) gave up her (turn) day and night to the mother of believers `Aishah (may Allah be pleased with her). However, the husband should do justice between them, if the granter changes her mind. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.