Gnuplot, how can I get hh:mm on x axis

Question

With this datafile (x.txt)

20180522110000 6.03
20180522144500 10.44
20180523071501 5.17

and this command file (x.gnuplot)

set term png
set output "x.png"
set xdata time
set timefmt "%Y%m%d%H%M%S"
set format x "%H:%M"
plot "x.txt" using :2 w lines

and using gnuplot 5.0 I don't get the desired x-labels. I get only

00:00   00:00   00:00   00:00 

not (something more like, give or take some details...)

11:00   ....  07:15

What am I doing wrong?

Answer 1

Solved it. I was missing "1"

Wrong:

plot "x.txt" using :2 w lines

Correct:

plot "x.txt" using 1:2 w lines