Matplotlib X축에서 타임스탬프 레이블이 겹치는 것을 어떻게 방지할 수 있습니까?

import sys

import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
import datetime

font = {'family' : 'normal',
        'weight' : 'bold',
        'size'   : 8}

matplotlib.rc('font', **font)

values = open('stats.csv', 'r').readlines()

time = [datetime.datetime.fromtimestamp(float(i.split(',')[0].strip())) for i in values[1:]]
delay = [float(i.split(',')[1].strip()) for i in values[1:]]

plt.plot(time, delay)
plt.grid(b='on')
plt.xticks(rotation=90)  # Rotate the X axis tick labels by 90 degrees

plt.savefig('test.png')