time measured as a stretch: how much of it passes, how long something lasts
Chronos is time counted out: a length, a span, a while. It answers the question how long, not the question what kind of moment. When the New Testament wants to say that years went by, that someone waited a long while, or that a fixed amount of time had run its course, this is the word it reaches for. English keeps the root in clock-and-calendar words like chronology and chronic.
The single idea of measured duration shows up in three everyday shades. Most often it simply means a quantity of time, long or short, that elapses or remains. Sometimes it pins down the exact point on the calendar when an event happened, the date or moment of a thing. And in the plural it can name whole stretches or epochs of history, the long periods God sets and oversees, especially when a writer lines it up against its partner word for the right moment.
Those are shades of one concept, not separate words: a reader uses the plain English word time for all of them. What changes is whether the focus falls on the amount of time, the point in time, or the eras of time. The crucial contrast is not inside chronos at all but between chronos and kairos: chronos is how much time, kairos is the loaded, decisive moment within it.