idevicedate: 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/idevicedate - from package: libimobiledevice-utils

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

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