Dividing one's time among co-wives; The Sunnah is for each one to have one night and one day

Sahih Muslim · Book 17 · Hadith 1462

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا شَبَابَةُ بْنُ سَوَّارٍ، حَدَّثَنَا سُلَيْمَانُ بْنُ الْمُغِيرَةِ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، قَالَ كَانَ لِلنَّبِيِّ صلى الله عليه وسلم تِسْعُ نِسْوَةٍ فَكَانَ إِذَا قَسَمَ بَيْنَهُنَّ لاَ يَنْتَهِي إِلَى الْمَرْأَةِ الأُولَى إِلاَّ فِي تِسْعٍ فَكُنَّ يَجْتَمِعْنَ كُلَّ لَيْلَةٍ فِي بَيْتِ الَّتِي يَأْ…

Anas (Allah be pleased with him) reported that Allah's Messenger (ﷺ) had nine wives. So when he divided (his stay) with them, the turn of the first wife did not come but on the ninth (day). They (all the wives) used to g…