def _prev_opening_time(self, other):
if not self.next_bday.onOffset(other):<EOL><INDENT>other = other - self.next_bday<EOL><DEDENT>else:<EOL><INDENT>if self.n >= <NUM_LIT:0> and other.time() < self.start:<EOL><INDENT>other = other - self.next_bday<EOL><DEDENT>elif self.n < <NUM_LIT:0> and other.time() > self.start:<EOL><INDENT>other = other - self.next_bday<EOL><DEDENT><DEDENT>return datetime(other.year, other.month, other.day,<EOL>self.start.hour, self.start.minute)<EOL>
If n is positive, return yesterday's business day opening time.
Otherwise yesterday business day's opening time.