the second was necessary because the actual situation was to fix the already existing function get_time(int t) which returned a datestring that was flagged by my spamfilter as being non-compliant.
apart from that, the usefullness would be that in unix time_t is used in a lot of places to store time values (say file access times and such) therefore i see a lot of situation where an existing time value != now needs to be evaluated.