title: How to add multiple custom ticks to seaborn boxplot
body: <p>I generated a boxplot using seaborn. On the x axis, I would like to have, both the number of days (20, 25, 32) and the actual dates they refer to (2022-05-08, 2022-05-13, 2022-05-20).
  I found a potential solution at the following link <a href="https://stackoverflow.com/questions/49471424/add-custom-tick-with-matplotlib">add custom tick with matplotlib</a>. I'm trying to adapt it to my problem but I could only get the number of days or the dates, not both.
  I really would appreciate any help. Thank you in advance for your time.
  Please, find below my code and the desired output.</p>
  <pre><code>import pandas as pd
  import matplotlib.pyplot as plt
  import seaborn as sns
  
  df = pd.DataFrame({'nb_days':[20,20,20,25,25,20,32,32,25,32,32],
               'Dates':['2022-05-08','2022-05-08','2022-05-08','2022-05-13','2022-05-13','2022-05-08','2022-05-20','2022-05-20','2022-05-13','2022-05-20','2022-05-20'],
               'score':[3,3.5,3.4,2,2.2,3,5,5.2,4,4.3,5]})
  
  df['Dates'] = df['Dates'].apply(pd.to_datetime)
  tick_label = dict(zip(df['nb_days'],df['Dates'].apply(lambda x: x.strftime('%Y-%m-%d')))) #My custom xtick label
  
  #Plot
  fig,ax = plt.subplots(figsize=(6,6))
  ax = sns.boxplot(x='nb_days',y='score',data=df,color=None)
  # iterate over boxes to change color
  for i,box in enumerate(ax.artists):
      box.set_edgecolor('red')
      box.set_facecolor('white')
  
  sns.stripplot(x='nb_days',y='score',data=df,color='black')
  ticks = sorted(df['nb_days'].unique())
  labels = [tick_label.get(t, ticks[i]) for i,t in enumerate(ticks)]
  ax.set_xticklabels(labels)
  
  plt.tight_layout()
  plt.show()
  plt.close()
  
  
  </code></pre>
  <p>Here is the desired output.</p>
  <p><a href="https://i.stack.imgur.com/xfJlT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xfJlT.png" alt="output" /></a></p>