In nine studies using archival data, surveys, and experiments, we identify a factor that predicts gender differences in time stress and burnout. Across academic and professional settings, women are less likely to ask for more time when working under adjustable deadlines (studies 1 to 4a). Women’s discomfort in asking for more time on adjustable deadlines uniquely predicts time stress and burnout, controlling for marital status, industry, tenure, and delegation preferences (study 1). Women are less likely to ask for more time to complete their tasks because they hold stronger beliefs that they will be penalized for these requests and worry more about burdening others (studies 1 to 2d). We find no evidence that women are judged more harshly than men (study 3). We also document a simple organizational intervention: formal processes for requesting deadline extensions reduce gender differences in asking for more time (studies 4a to 5).