gistfile1.sh

# minute   hour   day of month     month   day of week       command
#  0-59    0-23   1-31             1-12    0-7 (0/7 is Sun) 
30         18     *                *       *                root  /opt/vc/bin/tvservice -p ; /opt/vc/bin/tvservice -o
30         8      *                *       1-5              root  /opt/vc/bin/tvservice -p ; sudo chvt 6; sudo chvt 7