The importance of the office environment to the comfort, productivity and health of workers cannot be overstated. While extant literature has shown that the physical environment of an office has a significant influence on how workers' perform their duties and on their comfort and health, few studies have explored the part played by the length of time they spend in the office. Using our dataset of 5149 workers from across the globe, we investigated the influence of time spent in the office building and at workstations on the relationship between Indoor Environment Quality (IEQ) and workers' productivity, comfort and health. An analysis of variance (ANOVA), Pearson's correlation and multiple regression analyses were employed. Our findings showed that while those who spent less time at work were less influenced by IEQ factors, noise and air quality were predominant in predicting how those who spent more time at work felt about their productivity, comfort and health. Specifically, a relationship did not exist between all of the IEQ factors and their perception of health for workers who spent less time in the office building. Also, the time spent in the office had a greater influence on the relationship between IEQ and workers' comfort than on their productivity and health. Our findings are useful for measures that ensure office workers achieve required work-related tasks under the appropriate working conditions. They give essential insights into the appropriate length of time workers should spend in the office.