Definition: Overtime hours
Overtime hours included those worked in addition to those of the normal or conventional working week (or month). If, for example, 4 hours were paid at time and a half, enter 4, not 6. Overtime hours were often paid at an enhanced rate, or were compensated by time off in lieu. They included time worked at nights, weekends and public holidays, unless these were a part of the employee's normal working time (for example, shift-work). Only those overtime hours worked in the sample pay period should be included. Time off in lieu of unpaid work periods and travel time were not regarded as overtime.
Eurostat, "Statistics on the structure and distribution of earnings: Methods and definitions", Data 1995, 1998 Edition, Office for Official Publications of the European Communities, Luxembourg, 1999, p.15