A period of time during which a person is normally in a particular life state(noun)
WordNet. Princeton University. 2010.
Use "time of life" in a sentence
"Long after the time of life at which other species of rats are nibbling an independent way through the world, U. BANFIELDI clings resolutely to its parent, obtaining from her its sole sustenance."
"They were written at a time of life when I was bold in the pursuit of knowledge, never fearing to follow truth and reason to whatever results they led, and bearding every authority which stood in their way."
"Now physiological discomfort is an experience universal at one time of life or another; but the reaction to it is infinite in variety; and while part of it depends upon the congenital dispositions which are the common property of humanity, a larger part is contingent upon the psychogenetic factors which have stamped the individual."