Judaism is a tradition that is obsessed with time. We are concerned with the way that the year is divided into seasons, the seasons into months, the months into weeks, the weeks into days, the days into hours and the hours into minutes. We mark them all by the sight and cycle of the moon and the path of the sun in the sky. The approach of the sun to the horizon defines the beginning of the day and the appearance of three proximate stars defines the end of the day. For the purpose of circumcision and mourning, any part of the day is considered a day, but for the purpose of koshering glass a day is twenty-four full hours. And Shabbat and the holidays are not complete without eighteen minutes borrowed from the day before and forty-two minutes borrowed from the day after.
You would expect, therefore, for references to time in Hebrew to be excruciatingly specific. But "eit" has the generic meaning of "time." Certainly it is used to mean hour or season in some contexts, but "eit" is otherwise extraordinarily flexible and unusually vague.
The most famous use of the word is in the book of Ecclesiastes, set to music in translation by Pete Seeger. "A time to be born, a time to die" and all the other contrasts repeat the word "eit" as the poetic device. And while that first phrase sounds very specific – both birth and death are specifically timed in halakha and modern medicine – later phrases like "a time to love, a time to hate," "a time to cast away stones, a time to gather stones," "a time to laugh, a time to weep" are of uncertain length, and they rarely start and end with clear definition.
"Eit" is used in contrast to "z'man," which also means "time." But "z'man" implies something more specific; it is used to name the festivals. Pesach is "z'man cheiruteinu," the time of our freedom. Shavu'ot is "z'man matan torateinu," the time of the giving of our Torah. Sukkot is "z'man simchateinu," the time of our happiness.
So I think I would translate "eit" as "phase of life." A phase is a period of time that enters gradually and fades away, sliding into the next phase. When we talk about God's actions that are extraordinary wonderful and wonderments, we mean things that arrive like a sunset and depart with the twilight, only to roll into the slow emergence of the stars. When we express our gratitude to God in each phase of life, we acknowledge the ebb and flow of wonder, but the constancy of time in which wonder occurs.