#
# Very simple Gantt Chart
# Demonstrate using timecolumn(N,format) to plot time data from 
# multiple columns
#
$DATA << EOD
#Task start      end
A     2012-11-01 2012-12-31
B     2013-01-01 2013-03-14
C     2013-03-15 2014-04-30
D     2013-05-01 2013-06-30
E     2013-07-01 2013-08-31
F1    2013-09-01 2013-10-31
F2    2013-09-01 2014-01-17
F3    2013-09-01 2014-01-30
F4    2013-09-01 2014-03-31
G1    2013-11-01 2013-11-27
G2    2013-11-01 2014-01-17
L     2013-11-28 2013-12-19
M     2013-11-28 2014-01-17
N     2013-12-04 2014-03-02
O     2013-12-20 2014-01-17
P     2013-12-20 2014-02-16
Q     2014-01-05 2014-01-13
R     2014-01-18 2014-01-30
S     2014-01-31 2014-03-31
T     2014-03-01 2014-04-28
EOD

set xdata time
timeformat = "%Y-%m-%d"
set format x "%b\n'%y"

set yrange [-1:]
OneMonth = strptime("%m","2")
set xtics OneMonth nomirror
set xtics scale 2, 0.5
set mxtics 4
set ytics nomirror
set grid x y
unset key
set title "{/=15 Simple Gantt Chart}\n\n{/:Bold Task start and end times in columns 2 and 3}"
set border 3

T(N) = timecolumn(N,timeformat)

set style arrow 1 filled size screen 0.02, 15 fixed lt 3 lw 1.5

plot $DATA using (T(2)) : ($0) : (T(3)-T(2)) : (0.0) : yticlabel(1) with vector as 1, \
     $DATA using (T(2)) : ($0) : 1 with labels right offset -2


Click here for minimal script to generate this plot