set terminal png
set output 'pressure.png'
set xdata time
set timefmt "%b %d %H:%M:%S %Y"
# set title "Household Water Pressure" 
set ylabel "PSI" 
set yrange [0:100]
set xrange [*:*]
set xlabel " "
set grid
set size 1.2 ,0.5
set key top left

plot 'power.720' using 1:9 t "Maximum pressure" with lines lc rgb "red", \
     'power.720' using 1:8 t "Minimum pressure" with lines lc rgb "blue"