Evenings are getting warmer and longer, but you can kick back only if you aren’t at the office.

The bad news is your to-do list may dismantle your sunset-watching desires. But fortunately there’s good news. Andy Core has some work-smarter ideas to help you get home at a reasonable hour so that you can enjoy those warm summer nights.

The author of the new book “Change Your Day, Not Your Life: A Realistic Guide to Sustained Motivation, More Productivity, and the Art of Working Well” www.andycore.com, promises to help you become what he calls a “Thriver” — someone who works hard, meets or exceeds expectations, and enjoys high levels of personal and professional success, accompanied by (and this is the best part) lower stress levels.

Here is one of his strategies to help you change the way you approach your day—and get out of the office earlier:

Own up to your junk hours. “Junk hours” are a little like junk food: While they provide short-term pleasure, they contribute to long-term imbalance and exhaustion. For instance, junk hours might include chasing rabbit trails on the Internet, shooting the breeze with colleagues at the water cooler, checking email in order to avoid doing other work, or even attending an unnecessary meeting.

“In order to maximize each day, you need to own up to your junk hours,” Core instructs. “You need to identify when you’re going through the motions of work, versus when real work is being done. Don’t be ashamed that your junk hours exist, because everybody needs to take breaks and shift gears. Your task now is to exchange your low-value ‘junk’ activities for ones that build greater health and value into your workday.

“For instance, I know one woman who, instead of taking an endless string of coffee breaks, sets aside 20 minutes each afternoon to knit. I know another man who decided to spend his lunch hours either with friends or going to the gym, instead of trying to squeeze in more work around bites of a burger. In both instances, these scheduled breaks increased my friends’ energy levels and sense of well-being. They felt less of a need to take low-value breaks and began to experience more productivity. And yes, they began getting out of the office earlier, too.”