"It's not for sleeping,
the night garlanded
with zodiac stars.
The night, for one who knows,
is for staying awake."
http://www.accesstoinsight.org/tipitaka/kn/thag/thag.02.37.than.html
From: Theragatha 2.37
Sona Potiriyaputta
Translated from the Pali by Thanissaro Bhikkhu
For Free Distribution, as a gift of Dhamma, from Access to Insight and
Thanissaro Bhikkhu