Quote Originally Posted by alexsms View Post
this means 'daily routine', 'monotonous life'. But this looks like a slightly old-fashioned colloquial saying.
+1

In addition these days this saying is used for children to memorize what "сутки" means. "сутки" - is a time period of 24 hours. So if one sums up the duration of a day and the following night it will come to "сутки" of 24 hours.