Thirty-nine percent of workers admit they have called in sick to work to enjoy a day off during the summer vacation season, according to an online survey conducted by Harris Interactive for Kronos Incorporated.

The survey, which included 1,077 adults employed full-time, found that 30 percent of employees may call in sick this season to enjoy a day off. The survey also found that the most popular days to call in sick are Friday and Monday.

Kronos calls the phenomenon "seasonal absence syndrome."

When asked why they call into work sick to enjoy a day off, respondents' most-common responses were:

• I needed a mental health day;
• The weather was great and I wanted to enjoy the day; and
• My workload is heavy so I spontaneously take time off when I can.

The survey also asked employees to identify strategies employers can adopt to curb the prevalence of seasonal absence syndrome. Employees suggested establishing "summer Fridays" or enabling employees to take a half or full day off on Fridays during the summer season.

Other popular responses included providing more flexibility at work, such as telecommuting, compressed work weeks, and flex-time, as well as providing employees with paid time off (PTO) programs that give employees a bank of time to use at their discretion.