More Companies Are Offering This Cheap Work Perk to Keep Staff Happy During the Summer Don't have Summer Fridays? So sorry to hear that.

Are you at work on this glorious June Friday? This time next year, you might not be.

That's thanks to the rising popularity of "Summer Fridays," a magical perk that gives staffs the gift of time during the hazy, lazy days of summer when business often slows, beaches beckon and kids are home from school. While the perk varies by company, it often means staff have the flexibility to start their weekends early by either cutting the day short or taking the entire day off.

In a recent survey of more than 220 human resources managers, 42 percent said the organizations they work for offer some version of a "Summer Fridays" option. That's a 20 percent increase from 2015, according to CEB (now Gartner), the research firm that conducted the survey.

Related: Being a Work Martyr Doesn't Help You Advance Your Career, Study Finds

What accounts for this jump? A more stable job market, in part. As employees feel more confident about their job stability, CEB says, companies seek new ways to keep top talent from getting restless and looking elsewhere.

"Summer Fridays is one low-cost way to improve employee engagement, which in turn can increase employee productivity and drive business results," Brian Kropp, a human resources exec at CEB, now Gartner, said in an online release about the findings.

In fact, other research shows employees value flexibility during the summer more than being allowed to wear shorts and flip-flops or even an office picnic. The cheap perk can also do wonders for morale. A 2012 Harris survey found that 87 percent of those with summer hours felt it contributed to a healthy work-life balance and 76 percent of that group said it boosted productivity.

Related: Why 'Vacation-Shaming' Hurts You More Than Your Employees

There are any number of ways your company can find the summer hours option that works for your team. If staff members can't take full days off, you might consider allowing your team to work from home or to shift their hours, starting earlier and still working a full day.

Still, the perk only works if it's used. If yours is a hard-driving culture, you'll need to plan ahead to avoid the shame that many people feel in taking their hard-earned time off. Make sure extra workloads won't keep staffs tied to their desks. Tell managers to take advantage of their own summer hours to set a good example for their teams. And while you're at it, remind everyone of this research released earlier this year -- being a work martyr doesn't actually help you get ahead.