As is in Shri Sai Satcharita, by Hemadpant .. Chapter XXXVII Page 197

Om Sai Shri Sai Jaya Jaya Sai

Baba's dormitory has been already described.  One day He slept in the Masjid and on the next, in the Chavadi (a small building containing a room or two near the Masjid).  He slept in Masjid and in the Chavadi on alternate days.  This alternate sleeping in both these buildings went on till Baba's Mahasamadhi.  

Bow to Shri Sai - Peace be to all