The practice has received both advocacy and criticism. Putting clocks forward benefits retailing, sports, and other activities that exploit sunlight after working hours, but can cause problems for evening entertainment and for other activities tied to sunlight, such as farming. Although some early proponents of DST aimed to reduce evening use of incandescent lighting, which used to be a primary use of electricity, modern heating and cooling usage patterns differ greatly and research about how DST affects energy use is limited or contradictory.

What used to be the main draw on electricity?