> So just change the hours you work during the Winter
Only the petit bourgeoisie (and not all of them, because often the capital and labor portion of their support is separated in modern capitalist/mixed economies) both labor and have even the theoretical ability to direct the hours of the labor, and even there there is a coordination problem since there is value in aligning core work hours with others. In any case, because consistent hours are, ceteris paribus, slightly cheaper, rationally it will be more common for work not to move without mandated clock shifts.
EDIT: To clarify, more common than is the case with clock shifts, not more common than work having seasonal shifts. The latter may also be the case, but is not the conclusion just from the being a marginal cost that doesn't exist when clock shifts are mandated.