IANAL, but I beleive that most places which have such laws require the employer to make “reasonable accomodation” for such religious things. Depending on the business, it may or may not be reasonable to allow an employee to always be exempt from Saturday - or late Friday - work.
I most definitely agree. But my main point was that the Friday Afternoon service is no different than the Thursday (or Otherday) Afternoon service in this regard.
This can indeed be a real problem. Some rabbis say to use the schedules of the nearest Jewish community that does have a sunrise and sunset. Others simply say to avoid the situation. (There are other answers too, but too complicated to explain in this forum.)