A common shortcut is to treat “primary duty” as whichever task eats the most hours in a workweek — if an employee spends five hours a day on the register and two supervising, the register must be the primary duty. § 541.700(a) rejects that shortcut outright. “Primary duty” means the principal, main, major, or most important duty the employee performs, and the determination has to rest on all the facts of the particular case, with the major emphasis on the character of the employee’s job as a whole — not a stopwatch. The regulation lists four factors to weigh together: the relative importance of the exempt duties compared with the employee’s other duties, the amount of time spent on exempt work, how free the employee is from direct supervision, and how the employee’s salary compares with what the employer pays other employees for the same kind of nonexempt work.

Time spent is one of those four factors, and the regulation gives it real weight as a guide: employees who spend more than 50 percent of their time on exempt work will generally satisfy the primary duty requirement. But § 541.700(b) is explicit that time alone is not the sole test — nothing requires an exempt employee to spend more than half the workweek on exempt duties, and an employee who spends less than 50 percent of the time on exempt work can still meet the requirement if the other three factors support that conclusion. A manager who is rarely at the register but is closely watched and paid almost the same as the cashiers can fail the test despite the light register time; a manager who runs the register more than half the shift can pass it because the exempt duties still carry the greater weight, freedom, and pay.

Part of why hours can mislead is that not all the time an employee spends on exempt-adjacent tasks counts against the exempt column. Under § 541.703, work that is “directly and closely related” to exempt duties — recordkeeping, taking notes, using a computer to prepare the documents that exempt work requires — is itself treated as exempt work, provided it is not merely remotely related to, or completely unrelated to, the exempt duties — that is, provided it actually facilitates the exempt function rather than standing apart from it. That reclassification changes what the “time spent” factor is even measuring, which is one more reason a raw hours count can point to the wrong answer.