I just buy this for a friend . I have the white version of this clock , and this cheap , simple little thing have be wake I up on time for the past 14 year . it be still tick . could not tellyou when last I change the battery . the battery last pretty long before it die . I change it before that happene . anyways , it be the best and the cheapest . I can not understand the digital stuff , and I do not trust they . I will stick to the basics . simplicity equal less headache !