It is probably fair to say that the term analog in the clock context is used to describe the type of display rather than the modus operandi which is resolutely digital in order to distinguish it from the type of display that most people would recognise as being digital  As has been noted this is for all practical purposes true   The term digital does not necessarily mean that the output consists of displayed digits though can include it  Many years ago a constructional project appeared in an electronic magazine that presented the opposite connundrum  It was a clock with a digital display but the modus operandi was in fact analog