code: def timestamp_to_days(self, timestamp):
          '''convert log timestamp to days'''
          if self.tday_base is None:
              try:
                  self.tday_base = matplotlib.dates.date2num(datetime.datetime.fromtimestamp(timestamp+self.timeshift))
                  self.tday_basetime = timestamp
              except ValueError:
                  # this can happen if the log is corrupt
                  # ValueError: year is out of range
                  return 0
          sec_to_days = 1.0 / (60*60*24)
          return self.tday_base + (timestamp - self.tday_basetime) * sec_to_dayf timestamp_to_days(self, timestamp):
          '''convert log timestamp to days'''
          if self.tday_base is None:
              try:
                  self.tday_base = matplotlib.dates.date2num(datetime.datetime.fromtimestamp(timestamp+self.timeshift))
                  self.tday_basetime = timestamp
              except ValueError:
                  # this can happen if the log is corrupt
                  # ValueError: year is out of range
                  return 0
          sec_to_days = 1.0 / (60*60*24)
          return self.tday_base + (timestamp - self.tday_basetime) * sec_to_days
docs: convert log timestamp to days