The nature of paid work is transforming rapidly. These changes are particularly dramatic in the large and growing service sector where workers’ hours and work schedules often vary week-to-week and day-to-day. Workers receive their schedules as little as a few days in advance, can be asked to work on-call, and may find their shifts changed or cancelled at the last minute. Yet, there is an acute lack of existing data that would allow us to monitor these practices, estimate their consequences for worker and family wellbeing and mobility, and assess the effectiveness of company and legal interventions. With the Shift Project, we have developed an innovative method of data collection that we have used to collect survey data on scheduling practices and wellbeing from thousands of retail workers employed at large firms. The data has national coverage with oversamples of respondents in cities at the forefront of regulating these labor practices.