def _calc_timestamps(self, st_time, end_time):
<EOL>curr = datetime(st_time.year, st_time.month, st_time.day, st_time.hour,<EOL>st_time.minute, self.is_leap_year)<EOL>end_time = datetime(end_time.year, end_time.month, end_time.day,<EOL>end_time.hour, end_time.minute, self.is_leap_year)<EOL>while curr <= end_time:<EOL><INDENT>if self.is_possible_hour(curr.hour + (curr.minute / <NUM_LIT>)):<EOL><INDENT>time = DateTime(curr.month, curr.day, curr.hour, curr.minute,<EOL>self.is_leap_year)<EOL>self._timestamps_data.append(time.moy)<EOL><DEDENT>curr += self.minute_intervals<EOL><DEDENT>if self.timestep != <NUM_LIT:1> and curr.hour == <NUM_LIT> and self.is_possible_hour(<NUM_LIT:0>):<EOL><INDENT>curr = end_time<EOL>for i in list(xrange(self.timestep))[<NUM_LIT:1>:]:<EOL><INDENT>curr += self.minute_intervals<EOL>time = DateTime(curr.month, curr.day, curr.hour, curr.minute,<EOL>self.is_leap_year)<EOL>self._timestamps_data.append(time.moy)<EOL><DEDENT><DEDENT>
Calculate timesteps between start time and end time.

        Use this method only when start time month is before end time month.