The hours worked will vary depending on grade, specialism and hospital. There are standard working weeks with additional "on calls" as follows:
A standard working week for a doctor is 9am to 5pm, Monday to Friday = 40 hours.
In addition to the standard 40 hours, doctors usually work on-call. On-call includes evenings and weekends. When referring to an evening, it will be from 5pm to 9am, making an evening on call 16 hours. A weekend on-call will begin from 9am Saturday to 9am Monday, equalling 48 hours.
A doctor working as a locum for one month on a one in five on call will therefore work a minimum of 56 hours each week, with a possibility of one weekend (worth 48 hours).
The on-call ratio can vary from 1:3, 1:4, 1:5, and so on.
There are also shift systems that are more commonly used in A&E (Accident and Emergency). As the department is open 24 hours a day, 7 days a week, there are no standard hours of work and a shift system is implemented with hours ranging from 40 to more than 70 hours each week.
With some specialisms, hospital work and pay is organised by sessions. This is usually the case for anaesthetics doctors, who are booked by theatre time; they do a morning and an afternoon therefore two sessions each day.
Most locum doctors want to work as many hours as possible as you are paid for every hour you are on call. If you are only working for a couple of weeks this might be practical, but be careful not to overbook yourself. The pace of work in some UK hospitals is quite frantic (some Accident and Emergency Units see over 500 patients per day). Global Medics will always try to find you as many hours as possible in accordance with your instructions, even if that means having to do additional shifts at other hospitals.