def get_approximate_schedule_time_span_in_ut(self):
first_day_start_ut, last_day_start_ut = self.get_day_start_ut_span()<EOL>return first_day_start_ut, last_day_start_ut + <NUM_LIT> * <NUM_LIT><EOL>
Return conservative estimates of start_time_ut and end_time_uts.
All trips, events etc. should start after start_time_ut_conservative and end before end_time_ut_conservative

Returns
-------
start_time_ut_conservative : int
end_time_ut_conservative : int