Matplotlib uses its own format for dates/times, but also provides simple functions to convert which are provided in the dates module. It also provides various Locators and Formatters that take care of placing the ticks on the axis and formatting the corresponding labels. This should get you started:
import random
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
# generate some random data (approximately over 5 years)
data = [float(random.randint(1271517521, 1429197513)) for _ in range(1000)]
# convert the epoch format to matplotlib date format
mpl_data = mdates.epoch2num(data)
# plot it
fig, ax = plt.subplots(1,1)
ax.hist(mpl_data, bins=50, color="lightblue")
ax.xaxis.set_major_locator(mdates.YearLocator())
ax.xaxis.set_major_formatter(mdates.DateFormatter('%d.%m.%y'))
plt.show()
Result:
