Fix ‘date: command not found’ Error in Bash Script

I've installed a version of Ubuntu Server and although I'm fairly still fresh with Ubuntu, I'm trying to create a bash file to run a program in the background. More importantly, I'm trying to get a file nameto display correct and create it before I start running the program (I like my debug stuff).

However, here is my bash script:

 #!/bin/bash
 PATH="/var/log/servers/Game/"
 FILENAME="startup"
 EXT=".log"
 DATE=$(date +%d-%m-%Y)
 NEWFILE=${PATH}${FILENAME}_${DATE}${EXT}

I have verified that the file does exist in the PATH directory. However, the issue is with the date command. When I run the script bash -x game.sh this is what is displays.

 + PATH=/var/log/servers/Game/
 + FILENAME=startup
 + EXT=.log
 ++ date +%d-%m-%Y
 game.sh: line 5: date: command not found
 + DATE=
 + NEWFILE=/var/log/servers/Game/startup_.log
 + echo /var/log/servers/Game/startup_.log

I don't understand why it would say the command doesn't work, when I can go to the main console and run date and get a valid response.

Any help is greatly appreciated!