<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def seconds_passed(self):
 """Amount of time passed in seconds since the beginning of the year. In the first example, the year is only one minute and thirty seconds old: 90 The second example shows that the 29th February is generally included: 5184000 """

        return int((Date(self).datetime -
                    self._STARTDATE.datetime).total_seconds())