alarm-clock-applet: command not found

Have You tried accessing the binary with the full path?

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

[root@server ~]# echo $PATH

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/alarm-clock-applet - from package: alarm-clock-applet

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