Vanilla
convert -size 800x600 xc:white -font Nimbus-Roman-No9-L-Regular-Italic -pointsize 300 -gravity center -draw "text 0,0 '$(date +%H:%M)' " /tmp/display.bmp
convert -size 800x600 xc:black -fill white -font Nimbus-Roman-No9-L-Regular-Italic -pointsize 300 -gravity center -draw "text 0,0 '$(date +%H:%M)' " /tmp/display.bmp
/IT8951/IT8951 0 0 /tmp/display.bmp