A line in the Facebook Newsfeed from Новая Газета reads:
“Кто сегодня не выспался, тот православный.”
Which means literally “He who didn’t get enough sleep today, is orthodox”.
Why would an Orthodox person be under-rested today? Because yesterday was православное рождество (Orthodox Christmas) which in Russia/Ukraine is celebrated on the 7th of January but most of the festivities happen late on Christmas Eve. Well, in Russia 7th of January is a work day so all the people that were up late attending mass and doing their traditional feasts had to get up and go to work today.
Here is a very informative video about Christmas traditions in Western Ukraine, the traditions are quite similar in Russia, depending on how religious the family is.