Date.set_time_t

Sets the value of a date to the date corresponding to a time specified as a time_t. The time to date conversion is done using the user's current timezone.

To set the value of a date to the current day, you could write:

time_t now = time (NULL);
if (now == (time_t) -1)
// handle the error
g_date_set_time_t (date, now);