unsort of dates

Hello,

I am using time formatting with xdata, and the months are sorted
automatically.
Instead of [Sep..March], I get [Jan..Dec]
I would like to keep the order as it figures in the file (below). Any
idea?

Thanks a lot :),
Keren.

set xdata time
set timefmt "%b" # The dates in the file look like 10-Jun-04
set format x "%b" # On the x-axis, we want tics like Jun 10

mon load jobs av resp av sld av b-sld av wait bf rate waiting
sep 0.149 103 3218.66 1.86 1.85 129.79 0.01 0
oct 0.668 2397 11978.97 94.95 78.05 5978.36 0.61 11
nov 0.690 1989 18164.46 345.04 137.08 9944.58 0.70 3
dec 0.689 2310 17142.22 1695.44 84.84 7327.63 0.69 2
jan 0.758 2916 16045.75 186.88 71.66 6802.16 0.66 9
feb 0.798 2944 16732.70 191.03 95.88 9894.21 0.83 0
mar 0.725 2062 16789.34 244.45 96.42 8181.94 0.77 16
apr 0.721 2865 16063.19 150.26 73.50 7551.88 0.70 0
may 0.677 4068 10090.25 106.87 51.94 3888.20 0.61 5
jun 0.743 2712 14386.76 35.94 25.58 4406.09 0.57 0
jul 0.620 2180 17793.96 64.37 24.67 1595.55 0.29 2
aug 0.584 1944 15752.44 125.85 60.23 4261.65 0.53 0

.