Thomas Edison did not directly invent a device that changed the working hours of factories, but his inventions and management style had an indirect impact on industrial work practices. Edison is best known for inventing the commercially viable incandescent light bulb and developing an entire electrical distribution system, which allowed factories and homes to be illuminated after dark

. This electric lighting extended the potential working hours beyond daylight, enabling factories to operate longer or in multiple shifts, which contributed to changes in working hours during the industrial era. At his Menlo Park laboratory, Edison implemented new management techniques, including the use of a time clock to track working hours, which was innovative for the time

. His invention factory operated with long workweeks, often stretching from the typical 60 hours to 80 hours per week, with Edison himself working very long hours and expecting high productivity from his employees

. This intense work culture was part of his approach to invention and industrial productivity. The broader historical context shows that the Industrial Revolution and the introduction of factory time discipline-governed by clocks-transformed working hours from seasonal and daylight-limited schedules to fixed, clock-regulated shifts

. While Edison did not legislate or reform working hours, his inventions (notably electric lighting) and factory practices contributed to the shift toward longer and more regulated industrial working hours. In summary:

• Edison’s invention of the electric light bulb and electrical distribution system allowed factories to extend working hours beyond daylight

• He introduced time clocks and strict time management in his invention factory, influencing industrial work discipline

• His intense work ethic and factory culture exemplified the long working hours common in industrial settings before labor reforms

• Changes to working hours more broadly came through social reform and legislation, not directly from Edison’s inventions

Thus, Edison’s inventions and factory management helped enable and exemplify the shift in factory working hours during the industrial age but did not directly change working hours by invention or law.