python / matplotlib x-axis characters are overlapping

Question

import os
import matplotlib.pyplot as plt
from PyQt5 import QtGui

def draw_pic_sukub_single(pic, rows, str_selected_opt):
    img_name = 'image.jpg'
    plt.clf()
    dict_data = rows_to_dict(rows)
    print(dict_data)

    x, y = [], []
    for key_date in dict_data.keys():
        x.clear()
        y.clear()
        for list_data in dict_data[key_date]:
            x.append(list_data[0])
            y.append(list_data[dict_opt[str_selected_opt]])
        plt.plot(x, y, '-', label=key_date)

    plt.xticks(rotation=35, ha='right')
    plt.locator_params(axis='x')
    plt.savefig(img_name)
    pic.setPixmap(QtGui.QPixmap(os.getcwd() + '/' + img_name))

    return pic

graph image

I drew this graph, but the X-axis characters overlapped and I can't read it.

The X-axis data is..['00:00:00', '00:05:00', '00:10:00', '00:15:00', '00:20:00', '00:25:00', '00:30:00', '00:35:00', '00:40:00', '00:45:00', '00:50:00', '00:55:00', '01:00:00', '01:05:00', '01:10:00', '01:15:00', '01:20:00', '01:25:00', '01:30:00', '01:35:00', '01:40:00', '01:45:00', '01:50:00', '01:55:00', '02:00:00', '02:05:00', '02:10:00', '02:15:00', '02:20:00', '02:25:00', '02:30:00', '02:35:00', '02:40:00', '02:45:00', ...

I want to show the X-axis only '0h, 1h, 2h, 3h,...' like this. How should I fix it? Please help me. Thank you.