Whittaker W, Anselmi L, Nelson P, et al. - In this observational study, experts understood how the uptake of an extended primary care service in the evenings and weekend differed by day of week and over and understood patient demographics of users of the service and how these differed by type of appointment and to core hour users. Of 42,472 appointments, 65.33% were booked and attended (used). Usage of appointments was least on a Sunday at 46.73%. Prebooked appointments were less prone to be booked among age group 0–9 and to lead to patients not attending an appointment. Family practitioner appointments were increasingly less inclined to be booked with age compared with nurse appointments. Patients attending extended access appointments were younger in contrast with core hour patients. In conclusion, there is spare capacity in the extended access service, especially on Sundays, implying reconfigurations of the service may be required to enhance efficacy of delivering the service. Patient demographics recommend the service is utilized by a relatively younger population as that of those with core hour services. Patient demographics differed with the types of appointment given, these findings may aid healthcare providers in improving usage by altering appointment provision to local populations.