Adjusting date tick labels through Python matplotlib

Question

I would like to visualize xticklabels suitably by decreasing the frequency of each tick similar to here. Therefore, I found this example as a solution to eliminate the main issue (see below). Therefore, the code I got:

from matplotlib import pyplot as plt, dates as mdates
#Blank subplots
fig, axs = plt.subplots(4, 3, sharex='col', sharey='row', figsize = (6,3), dpi = 140)
    
#Loop through each chart in the subplot
for count, ax in enumerate(axs.reshape(-1)):
    ax.plot(dfN[count]["Tarih"], dfN[count]["PM10"])
    ax.xaxis.set_major_locator(mdates.MonthLocator(bymonth=(1, 7)))
    ax.xaxis.set_minor_locator(mdates.MonthLocator())    
    ax.xaxis.set_major_formatter(mdates.DateFormatter('%Y-%b'))
    for label in ax.get_xticklabels(which='major'):
        label.set(rotation=30, horizontalalignment='right')

plt.show()

However, this one throws further issue as below:

The date is not starting with my actual date data. It is starting with 1970.

The main issue:

Any suggestions ? Thanks