Employers should set out in the employment contract how the daily rate of pay of an employee on an annual salary is to be calculated for various purposes, particularly if the employee does not have fixed regular hours and the employer wishes to apply a rate other than 1/365.

In Hartley v King Edward VI College the Supreme Court held that teachers employed on annual contracts, and who worked on unspecified weekends as well as weekdays as part of the core duties, were to be treated as accruing pay at 1/365 salary per day, in the absence of any express provision to the contrary. The employer was therefore only entitled to make deductions from the teachers' pay at the rate of 1/365 (and not 1/260 as contended) for each day of strike action.