Impermanence is intimately connected with time:

… But “later” is the safest of all time frames. It can be safely ignored because it’s not now—it’s later, and later never comes. And even if it does, we don’t have to worry about it now. We can worry about it later. For most of us most of the time, impermanence seems irrelevant.

But in truth, impermanence isn’t later; it’s now. The Buddha said, “All conditioned things have the nature of vanishing.” Right now, as they appear before us, they have that nature. It’s not that something vanishes later. Right now, everything is in some way—though we don’t understand in what way—vanishing before our very eyes. Squeezing uncomfortably through the narrow doorway of now, we don’t know whether we are coming or going.
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Of course, time is impermanence and impermanence is time! Time is change, development, and loss. Present time is ungraspable…