Part-time contract. A part-time contract is a form of employment that carries fewer hours per week than a full-time job. They work in shifts. The shifts are often rotational. Workers are considered to be part-time if they commonly work fewer than 30 hours per week. According to the International Labour Organization, the number of part-time workers has increased from one-fourth to a half in the past 20 years in most developed countries, excluding the United States.