Diagnostic appointments last at least three hours, but may sometimes involve up to eight hours of testing. Diagnostic assessments are often required to decide if patients are likely to be candidates for epilepsy surgery, or when diagnosing young onset dementias. Most people complete their evaluation on a single day, but sometimes we need to ask people to return for a second or even third time. We know our tasks are quite tiring and so we encourage people to pace themselves and take rest and refreshment breaks. Return visits are organised when long or complex series of tests are required, when people have limited energy, or when we want to see if there has been any change in function across an interval of months or years.