ntpdate-debian: 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/sbin/ntpdate-debian - from package: ntpdate

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

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