ccal: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/ccal - from package: ccal

You may install the required package with command apt-get install {package}

Error in other languages:
ccal: bevel nie gevind nie
ccal: comandă negăsită
ccal: comando não encontrado
ccal: commande introuvable
ccal: command not found
ccal: käsku ei ole
ccal: không tìm thấy lệnh
ccal: komanda nerasta
ccal: Kommando nicht gefunden.
ccal: kommandot finns inte
ccal: komut yok
ccal: nie znaleziono polecenia
ccal: níor aimsíodh an t-ordú
ccal: no se encontró la orden
ccal: no s'ha trobat l'ordre
ccal: opdracht niet gevonden
ccal: parancs nem található
ccal: perintah tidak ditemukan
ccal: príkaz nenájdený
ccal: příkaz nenalezen
ccal: команда не найдена
ccal: командата не е открита
ccal: 命令找不到
ccal: コマンドが見つかりません