tty-clock: 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/tty-clock - from package: tty-clock

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

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