wmdate: 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/wmdate - from package: wmdate

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

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