title: Set xlim of time series in matplotlib
body: <p>I want to draw a plot in matplotlib that shows the temperature of August in 2016 and 2017. x-axis is time and y-axis is temparature. I try to stack 2 plots (one for 2016, one for 2017) on top of each other by sharing the x-axis that ranges from 2016-08-01 00:00:00 to 2016-08-31 23:00:00 and showing only the day of the month. </p>
  
  <pre><code>import matplotlib.dates as mdates
  myFmt = mdates.DateFormatter('%d')
  
  # times series from 2016-08-01 00:00:00 to 2016-08-31 23:00:00
  x = stats_august_2016.MESS_DATUM
  # temperature in 08.2016
  y1 = stats_august_2016.TT_TU
  # temperature in 08.2017
  y2 = stats_august_2017.TT_TU
  
  f, ax = plt.subplots()
  
  # plot temp in 08.2016 
  ax.plot(x, y1, 'yellow', label = '2016')
  # plot temp in 08.2017 
  ax.plot(x, y2, 'red', label = '2017')
  # format x-axis to show only days of the month  
  ax.xaxis.set_major_formatter(myFmt)
  ax.grid(True)
  
  plt.rcParams["figure.figsize"] = (12, 8)
  plt.xlabel("Day of the Month", fontsize = 20, color = 'Blue')
  plt.xticks(fontsize = 15)
  plt.ylabel("Temperature ($\degree$C)", fontsize = 20, color = 'Blue')
  plt.yticks(fontsize = 15)
  ax.set_ylim(5, 35)
  plt.title("Temperature in August 2016 and 2017", fontsize = 30, color = 'DarkBlue')
  plt.legend(prop = {'size': 20}, frameon = True, fancybox = True, shadow = True, framealpha = 1, bbox_to_anchor=(1.22, 1))
  plt.show()
  </code></pre>
  
  <p>Everything looks fine except the last tick of x-axis is somehow 2016-09-01 00:00:00. And the result looks odd with the 1 at the end.</p>
  
  <p><a href="https://i.stack.imgur.com/odbzZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/odbzZ.png" alt="enter image description here"></a></p>
  
  <p>How can I fix this?</p>