According to the calendar, September is just another month in the year. But according to our emotions, this time of year often feels particularly weighty.

With summer at an end, many people experience a pang of nostalgia for the good weather and days off (and sometimes regret that they didn't make the most of them). For parents and students, the back-to-school period is often a potent cocktail of relief, excitement, and anxiety.

But even if your summer was uneventful and you're long past your student days, September often still feels important. After at least 13 years of experiencing the ninth month of the year as a new beginning, most of us have a hard time shaking the sensation that September offers a sort of reset button on life.

"For many of us, September is the other January--time to make a fresh start," author Gretchen Rubin wrote recently on Facebook, summing up the feelings of many.

The scientific case for starting afresh in September.

And as Science of Us blogger Melissa Dahl notes in her fun and useful post pointing to Rubin's writings on the odd power of September, there's a good scientific reason why this should be so. Thanks to the academic calendar, she writes, September is what's known as a "temporal marker," a life transition when one era feels like it ends and another begins.

Even if a temporal marker is based on something flimsy like your recollection of your time as a student, it's still a potentially powerful springboard for change, Dahl explains. Research shows that we tend to view these life shifts as a fresh start, a time when we have the freedom to become a new, better version of ourselves.

"People don't just use these landmarks to organize the memories of their lives; we use them to organize memories of ourselves, too," she says, citing a 2014 study out of Wharton. "It's a way of distancing your current, much more on-top-of-things self from past versions of you, who were maybe not so on-top-of-things." In short, temporal landmarks, including the ghost of the beginning of school years past, are a perfect time to unveil a whole new you (even if just to yourself).

So if you're thinking of starting a new routine, beginning a big project, or committing to learning something fresh and September feels like a natural time to get cracking, don't think you'd do better if you waited until January. This month really does have its own weird power to help people begin afresh.

A word of caution.

One final word of caution, however: While the "fresh start effect" of temporal landmarks is scientifically validated and potentially useful, it does fade fast.

So while you can rely on that new-school-year feeling to get you started on your new project, don't expect it to have enough force to push you through to its conclusion. You're going to have to rely on other longer-term motivation strategies for that. Handily, I've written about several of them.