How to customize x-axis tick interval

I have some problem with setting x-axis tick interval.
I Have a date[‘01.13’, ‘01.14’, ‘01.15’, ‘01.16’, ‘01.17’, ‘01.18’, ‘01.19’, ‘01.20’, ‘01.21’, ‘01.22’, ‘01.23’, ‘01.24’, ‘01.25’, ‘01.26’, ‘01.27’, ‘01.28’, ‘01.29’, ‘01.30’,… ‘05.27’].
And I wanna plot graphy about like
confirm(date),suspect(date),heal(date),death(date)
But the xtick label is too many had been overlapped.
Q1:modify interval（x-axis tick labels are like 01.13,01.23,02.02….）
Q2:Does step will be easier if turn ‘date[]’ into format of‘datetime’ ?And how to transform ?

x=[]
y1=[]
y2=[]
y3=[]
y4=[]
for day_item in china_day_list:
    date = day_item['date'] #+ '.2020'
    confirm = day_item['confirm']
    suspect = day_item['suspect']
    dead = day_item['dead']
    heal = day_item['heal']
    nowConfirm = day_item['nowConfirm']
    nowSevere = day_item['nowSevere']
    deadRate = day_item['deadRate']
    healRate = day_item['healRate']
    ############plt
    x.append(date)
    y1.append(confirm)
    y2.append(suspect)
    y3.append(dead)
    y4.append(heal)

plt.figure(figsize=(20, 8))
plt.title('line graph of disease with time', fontsize=16)
plt.plot(x, y1, 'r-', label='C')
plt.plot(x, y2, 'b-',label='S')
plt.plot(x, y3, 'y-',label='D')
plt.plot(x, y4, 'g-',label='H')



plt.gcf().autofmt_xdate() # rotate label

plt.legend() #