Shifting the onus to the employee to seek voluntary shift switches with co-workers may be considered a reasonable religious accommodation.
In Sanchez-Rodriguez v. AT & T, Mr. Rodriguez was a sales person required to work Saturdays. He became a Seventh Day Adventist, which proscribes work on Saturdays. He sought religious accommodation from AT & T, which asserted that Saturday work was an essential function. The company offered him a different (lower paying) job or Mr. Rodriguez could seek voluntary shift swaps with co-workers. The company would provide him with work schedules and allow him to post his swap request on the company bulletin board.
The First Circuit upheld AT & T’s offers as reasonable accommodation.