OBJECTIVES: We examined trends in the socioeconomic distribution of work schedules from 1990s to 2010s and how early adulthood disadvantages are associated work schedules over working age. METHODS: In a representative sample of U.S. workers(N = 3,328), we calculated recycled predictions of day, evening, night, and long shift prevalence associated with time-period. Logistic regression was used to analyze the association of non-day shifts with age and its variations by early adulthood disadvantage in U.S. baby boomers(N = 10,293). RESULTS: Between 1990s-2010s, evening shifts increased in adults without college education and night shifts increased in the lowest income quartile. Day shifts decreased in both groups. Being Black, not attending college, and poverty were associated with non-day shiftwork throughout working age. CONCLUSIONS: Evening and night shifts may have replaced day shifts in disadvantaged populations between 1990s-2010s. Early disadvantages may have sustained effects on work schedules.