A simple, though not particularly elegant, solution, is to write a wrapper script that executes your target script on the specified days, and call the wrapper script from cron.
eg (of the top of my head, not tested):
Code:
#!/bin/bash
FLAGFILE=/var/tmp/FlagFileNameThatIsUnique
DAY=`date +\%a`
case $DAY in
Mon) /path/to/script/to/be/run;;
Thu) [ -f $FLAGFILE ] && rm $FLAGFILE || (/path/to/script/to/be/run; touch $FLAGFILE);;
esac
set the cron entry to call the wrapper every monday and thursday.
The wrapper will only run the script on a thursday if the flagfile doesn't exist (and create the flagfile, once it has run). The next time it gets called on a thursday the flagfile will exist, so it doesn't run the script, just deletes the flagfile.
You may want to be careful where you store the flagfile, as on your system /tmp and /var/tmp may be 'cleaned' if the system is rebooted. You also have to ensure that the flagfile is uniquely named, so that nothing else can interfere with it.
