chronyd: 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 CentOS possible default full paths are:

/usr/sbin/chronyd - from package: chrony

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/chronyd - from package: chrony

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

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