The part of a day in which work is done; the number of hours one must work per day for a specified wage.
Any of those days of a week on which work is done, officially Monday to Friday in many countries (even though many people work on weekends).
The period of time that an individual spends at paid occupational labor. Most countries regulate the working time by law, e.g. by stipulating a maximum number of working hours per week. Exact definition varies by the legislation.