chron·o·bi·ol·o·gy 
(krŏn′ō-bī-ŏlə-jē)
(krŏn′ō-bī-ŏlə-jē)n.
The study of the effects of time and rhythmical phenomena on life processes.
chron′o·bi·o·logic (-ə-lŏjĭk), chron′o·bi·o·logi·cal (-ĭ-kəl) adj.
chron′o·bi·o·logi·cal·ly adv.
chron′o·bi·olo·gist n.