gnome-schedule: 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/gnome-schedule - from package: gnome-schedule

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

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