An Advair Diskus is routine asthma inhaler that is taken in the morning and lasts all day. However some people's breathing is worse during other parts of the day and should be started at other times. An Advair Diskus is most potent in waves as the body uses it. With a daily dosage journal they will be able to calculate and track how their breathing is doing in various parts of the day and allow them to vary their usage.