plots a graph of the modification times of all the files in ~/src (year on x-axis, hour on y-axis)

make

#!/bin/bash
find ~/src -printf '%CY-%Cm-%Cd %CH %CM\n' | \
awk '{print $1" "$2"."($3/59)*100;}' | \
sed 's/\.[^.]\+$//' > times.dat

gnuplot plot.gp > plot.png

plot.gp

set xdata time
set timefmt "%Y-%m-%d"
set format x "%Y"
set xlabel 'year'
set ylabel 'hour'
set yrange [0:24]
set ytics 1
set xtics 365*24*60*60
set terminal png size 800,600
plot "times.dat" using 1:2 title 'mod time' with points