A hearing aid adapted for issuing, at at least one predetermined notification time, a notification to a hearing aid user wearing the hearing aid. The hearing aid comprises digital circuitry (16, 17) including a digital processor (16), means (18) for generating a first time base for the digital circuitry (16, 17) of the hearing aid, digital storage means (13) for storing data corresponding to at least one time limit at which a notification is to occur. The hearing aid also comprises digital storage means (12) for storing a compensation factor value indicating a relative difference between saidfirst time base and a second external time base. Furthermore the hearing aid comprises means for determining, based on said data indicating the predetermined notification time, said first time base and said compensation factor value, when said predetermined notification time has been reached and issuing the notification.