[Gnuplot-info] trouble protting timediff

[walter h. <wh...@bf...>]

hi list,
the idea here was to plot the time difference ($2-$1) vs value (3).
The results are confusing and i have no idea what the problem may be
(me or gnuplot).
the x-axes i see is 0 0 1 1 2 2 3
but i expected to see the time difference in seconds.

note: yes i can preprocess that file and use seconds in the first place
      but i would like to understand what is going on here

note: this is a simplified example

# from          to     value
  1990-01     1990-06   27
  1990-01     1991-12   35
  1989-12     1992-01   22


set timefmt "%Y-%m"
set xdata time
set format x "%s"   # seconds to illustrate the problem
plot "test.dat" using ($2-$1):3 with p ps 2 pt 5