It can be the sight of a school bus picking up or dropping off its cargo that prompts the realization that the recent languid months of summer are on the wane.
Labor Day weekend, of course, is another obvious signal. Or maybe it's a couple of trees which are already starting to change color.
Summer should be a relaxed and carefree time, and the opportunity to sit and enjoy the warm weather - although this summer had its erratic moments in that regard. It is a useful antidote to the more hectic and purpose-driven times that characterize so much of the rest of the year. That's of course changing. Indeed, it's already changed.
Technology saves time and labor on the one hand, and gives us the opportunity to do more on the other. Like responding to the deluge of email. Or posting to Facebook. Or tweeting. Or is it twittering?
Fortunately autumn is far from unpleasant and filled with charms of its own. What's not to like about the brilliance of the fall foliage, the cooler nights and this year, at least, the absence of an overheated political campaign? Time for that will come soon enough.
Still, it's hard not to miss those long days when darkness waits until after 8 p.m. to show up. Oh well.
Soon the state parks and swimming places like the quarry will once again thin out and be reclaimed more or less by nature.
Schools will be teeming again with their students. Time to get back to work. But perhaps there will still be a few more weeks of "Indian summer" left to remind us and keep fresh what has passed by these last few months, to help us reflect and take a needed "time out."
Taking time outs aren't an inefficient waste of time - we need them to help us make sense of the rest of it.
Andrew McKeever is the managing editor of the Manchester Journal.