I use Python 2.7 and matplotlib. I have a *.txt data file :
0 14-11-2003
1 15-03-1999
12 04-12-2012
33 09-05-2007
44 16-08-1998
55 25-07-2001
76 31-12-2011
8
This code will do what you're looking for. It's based on examples found here and here.
The autofmt_xdate() call is particularly useful for making the x-axis labels readable.
import numpy as np
from matplotlib import pyplot as plt
fig = plt.figure()
width = .35
ind = np.arange(len(OY))
plt.bar(ind, OY, width=width)
plt.xticks(ind + width / 2, OX)
fig.autofmt_xdate()
plt.savefig("figure.pdf")
