title: axes.set_xticklabels breaks datetime format
body: <p>im trying to force my will onto this matplotlib graph. When I set <code>ax1.xaxis.set_major_formatter(myFmt)</code> it works fine like in the <a href="https://i.stack.imgur.com/OEMbT.png" rel="nofollow noreferrer">upper graph</a>.
  However when I add  <code>ax1.set_xticklabels((date),rotation=45)</code> the timeformat reverts to matplotlib time like in the <a href="https://i.stack.imgur.com/OEMbT.png" rel="nofollow noreferrer">lower graph</a>.</p>
  
  <p>Both use the same input time variable. I also tried <code>ax1.plot_date()</code> but that only changes the look of the graph not the timeformat.,</p>
  
  <pre><code>    date_1 = np.vectorize(dt.datetime.fromtimestamp)(time_data) # makes a datetimeobject from unix timestamp
      date = np.vectorize(mdates.date2num)(date_1) # from datetime makes matplotib time
      myFmt = mdates.DateFormatter('%d-%m-%Y/%H:%M')
  
      ax1 = plt.subplot2grid((10,3), (0,0), rowspan=4, colspan=4)
      ax1.xaxis_date()
      ax1.plot(date, x)
  
      ax1.xaxis.set_major_formatter(myFmt) 
      ax1.set_xticklabels((date),rotation=45)#ignores time format
  </code></pre>
  
  <p>Any ideas how I can force the custom timeformat onto the xticklabels? I get that xticklabels directly reads and displays the date variable but shouldnt it be possible to make it stick to the format? Especially if you later want to add xticks in custom date locations.</p>
  
  <p>All ideas appreciated. Cheers</p>