There are two main qualifying periods of continuous employment for acquiring employment rights. Unfair dismissal has a qualifying period of one year's continuous service and redundancy pay entitlement requires two years' continuous service. Some contractual rights for teachers and school staff such as sick pay are based on length of continuous service. Statutory notice entitlement is based on continuous service. All employees are entitled to a minimum of one week's notice for each year of continuous employment up to a maximum of twelve weeks.
The rules for continuity of employment are set out in the Employment Rights Act 1996. In some circumstances a period of time can count towards continuity of employment even though there is no contract of employment. This includes any week when the employee is absent from work “on account of a temporary cessation of work”. In the important case of Ford v Warwickshire County Council 1983 IRLR 126 the House of Lords considered what a “temporary cessation of work” was in the context of a succession of short term contracts with holiday breaks in between. A pottery teacher at an technical college was employed for eight years under yearly contracts for each college year, September to July. The House of Lords ruled that she had continuous employment.
In a more recent case, Prater v Cornwall County Council  EWCA Civ 102, the Court of Appeal considered the case of a teacher who had worked for the Council's Home Tutor Service for ten years. She was allocated pupils who were unable to attend school. Arrangements for tuition had to be flexible. Teachers were not guaranteed a minimum amount of work and were not obliged to accept work offered to them. The Court of Appeal decided that she did have employment rights. Each assignment was a period of employment and the downtime between assignments was a temporary cessation of employment following the judgment in Ford v Warwickshire County Council.