When asking a modern worker what time his or her workday ends, don't be surprised if the response is, "Which one?" In fact, according to the latest WorkSphere survey from Spherion Staffing, the typical worker's obligations may just be getting started once 5 p.m. hits.

The Spherion survey, conducted online in April 2017 with global market research organization Research Now, found that 85 percent of workers hold at least one side gig, or secondary source of employment, in addition to their primary job. Of that group, more than half (54 percent) hold two or more side gigs, extending their skills across multiple roles and fields of work.

Not surprisingly, financial incentives are the primary driver behind employees' search for extra work. Among workers holding at least one side gig, a desire to supplement their current income (42 percent) and make money to save for future interests and responsibilities (37 percent) were the most frequently cited reasons for doing so. In particular, more than half (57 percent) of female workers deemed income growth the main inspiration for their side gig activity, far surpassing the volume of male workers (31 percent) who said the same.

However, for some employees, a side gig generates a return beyond the wallet. Spherion found that many workers engage in side gigs that allow them to try something different or be involved with a hobby or cause of interest, with 26 percent of those interested in picking up a side gig in the next year preferring to do so in a space not at all related to their primary job. Additionally, 45 percent of respondents seeking gigs outside of their main field said they would still take part in a side gig even if it did not generate significant income.

"The escalating interest in side gigs across the American workforce does not necessarily reflect that workers are unhappy with their job, but rather a desire to pursue new and exciting growth opportunities – be they financial or personal," said Sandy Mazur, Spherion Division President. "Given this growth, side gig flexibility must be taken into account as companies refine their recruitment and retention plans. Employers and employees must find a middle ground that gives workers freedom to explore supplemental opportunities without inhibiting productivity or performance."

While many businesses encourage employees to take part in side gigs, and even see potential for them to transfer skills learned in these roles to their primary job, significant concerns remain from both parties around how to achieve a successful balance. Forty percent of businesses have formal policies regarding employees' side gig involvement, namely to avoid possible conflicts of interest and keep them focused on essential work. Employees seem to echo these feelings, with 48 percent expressing concern that their side gig efforts could interfere with their main job responsibilities.

Additionally, Spherion uncovered several other noteworthy trends regarding how employers and employees approach the escalating side gig movement:

The Right Side…?

• Nearly half (47 percent) of workers say that changing societal norms have set the expectation that at least one side gig is necessary.

• Among workers holding at least one side gig, 18 percent said they are doing so because it is considered standard in the modern workforce.

Taking Sides:

• One-fourth (25 percent) of workers who have never before held a side gig say they are "extremely" or "very" likely to pick one up in the next year, with millennial workers (43 percent) leading the charge.

• Side gigs are top of mind for today's workers – nearly two-thirds (65 percent) of those who have never held a side gig said they have at least given it some thought.

Keep it Out, Side:

• More than half (51 percent) of workers would prefer that their colleagues not discuss their side gigs at the office.

• A nearly equal number (48 percent) have taken vacation time or time away from their primary job to focus on their side gig.

• Despite potential mixed responses, many workers still feel comfortable discussing their side gigs with their colleagues (82 percent), manager (74 percent) and other senior leaders (73 percent) at their primary job.