MHz:
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.
I think there is a confusion on what to do to get what you want to achieve.
if you want to use the standard library, then because "Arduino is not a watch" 
and thus it does not know what time it is, you need to first initialize the time in your arduino.
See this and that time GPS example
Once this is done, time functions from the Arduino Time library are available
so
time_t t = now(); // Store the current time in time variable t
then your pointer is just &t
It might be confusing why we need to pass a pointer to the time_t value, I would guess that in the early days of computing the time() function could not directly return a long int and thus the data was passed by reference...