def yaxis_date(self, tz=None):
ymin, ymax = self.dataLim.intervaly<EOL>if ymin==<NUM_LIT:0.>:<EOL><INDENT>dmax = today = datetime.date.today()<EOL>dmin = today-datetime.timedelta(days=<NUM_LIT:10>)<EOL>self._process_unit_info(ydata=(dmin, dmax))<EOL>dmin, dmax = self.convert_yunits([dmin, dmax])<EOL>self.viewLim.intervaly = dmin, dmax<EOL>self.dataLim.intervaly = dmin, dmax<EOL><DEDENT>locator = self.yaxis.get_major_locator()<EOL>if not isinstance(locator, mdates.DateLocator):<EOL><INDENT>locator = mdates.AutoDateLocator(tz)<EOL>self.yaxis.set_major_locator(locator)<EOL><DEDENT>if self.viewLim.intervaly[<NUM_LIT:0>]==<NUM_LIT:0.>:<EOL><INDENT>self.viewLim.intervaly = tuple(self.dataLim.intervaly)<EOL><DEDENT>locator.refresh()<EOL>formatter = self.xaxis.get_major_formatter()<EOL>if not isinstance(formatter, mdates.DateFormatter):<EOL><INDENT>formatter = mdates.AutoDateFormatter(locator, tz)<EOL>self.yaxis.set_major_formatter(formatter)<EOL><DEDENT>
Sets up y-axis ticks and labels that treat the y data as dates.

        *tz* is the time zone to use in labeling dates.  Defaults to rc value.