thank you J-M-L for jumping in. As a non native speaker GoForSmokes answer "...Arduino is not a watch company" makes no sense to me nor seems it related to my question.
I've already mentioned that I receive and process NTP time stamps (primarily from german time server at ptb). No problem with receiving time/date strings delivered by an DCF77 receiver, more over I own a gps receiver from which I get time and geographical data. No problem by adding a DS1307 RTC however how is this related to my question???
All I asked for was "...how to use and set the pointer in time_t time ( time_t * timer) " module/function/methode you name it.
It's up to you GoForSmoke or any other Arduino community member to answer this (simple and maybe silly newbie) question. Either status nor karma rate counts, it should just be a working solution.
Thank you all