Working time is the period of time that an individual spends at paid occupational labor. Unpaid labors such as personal housework or caring for children/pets are not considered part of the working week. Many countries regulate the work week by law, such as stipulating minimum daily rest periods, annual holidays and a maximum number of working hours per week. Working time may vary from person to person often depending on location, culture, lifestyle choice, and the profitability of the individual's livelihood. For example, someone who is supporting children and paying a large mortgage will need to work more hours to meet a basic cost of living than someone without children of the same earning power. As fewer people than ever are having children choosing part time is becoming more popular.