<p>Studies have shown that working nonstandard schedules is prevalent in developed economies, which may have implications for individuals’ health and wellbeing. Existing research typically relies on survey data using two measurement approaches: requiring respondents to choose either a standard or nonstandard schedule, or allowing them to indicate whether they work both schedules. This study examined whether these measurement approaches affect the estimated prevalence and health consequences of nonstandard work schedules, using a sample of parents with preschoolers in Hong Kong. Results indicated that the prevalence of nonstandard work schedules was approximately 1.77 times higher when respondents could choose multiple schedules. The negative association between working nonstandard schedules and health outcomes was weaker when respondents were limited to choosing only one schedule, as this approach was unable to identify those working both standard and nonstandard schedules, who were most vulnerable to the adverse health effects of nonstandard work schedules. These findings suggest that asking respondents to select only one schedule may underestimate both the prevalence and the negative health consequences of nonstandard work schedules.</p>