six in the morning
This I was not slow to observe . I felt the desire to sleep come upon me at regular periods , and I concluded , therefore , that whenever I had this feeling upon me it was about ten o'clock of the night . I had discovered , too , by registering the time with my watch , that I usually slept about eight hours , and then I felt no desire to remain asleep any longer . When I awoke it would be six in the morning ; and , in this belief , I regulated my watch to that hour . So convinced was I of these facts , that I felt confident I could have counted the days without the watch ; but fearing that some change might occur in my habitual hours of rest , in consequence of the altered circumstances in which I was placed , I resolved always to keep the time-piece going . Ever before lying down to sleep , I took the precaution to wind it up to the full length of its chain , and on awaking I repeated the operation , so that there might be no danger of even a moment 's stoppage . Though satisfied that I could tell night from day , I have said that it mattered little , or not at all .