Strangely, yesterday when I tried what you suggested (adding the absolute path of wol to the command), it worked, and I set the cron job to 4PM (16.00) everyday. Today, at 3.55PM, I was randomly chatting on my laptop and suddenly remembered that normally, my server should wake up at 4PM.. it didnt…. I wonder why!?
I tried to manually launch the script via the pfsense web config (command) but it did not work. I noticed everytime I launch the script, my router's light would flash all at one. I imagine this means that the pfsense machine is effectively broadcasting a wol command to the network. However, on my laptop, I successfully woke up the server using "wol 192.68.0.101"... nothing more.
Is there an incompatibility between freebs and linux (slackware)?