pear-dh-ini2xml: 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 CentOS possible default full paths are:

/usr/bin/pear-dh-ini2xml - from package: php-pear-Date-Holidays

You may install the required package with command yum install {package}
Error in other languages:
pear-dh-ini2xml: bevel nie gevind nie
pear-dh-ini2xml: comandă negăsită
pear-dh-ini2xml: comando não encontrado
pear-dh-ini2xml: commande introuvable
pear-dh-ini2xml: command not found
pear-dh-ini2xml: käsku ei ole
pear-dh-ini2xml: không tìm thấy lệnh
pear-dh-ini2xml: komanda nerasta
pear-dh-ini2xml: Kommando nicht gefunden.
pear-dh-ini2xml: kommandot finns inte
pear-dh-ini2xml: komut yok
pear-dh-ini2xml: nie znaleziono polecenia
pear-dh-ini2xml: níor aimsíodh an t-ordú
pear-dh-ini2xml: no se encontró la orden
pear-dh-ini2xml: no s'ha trobat l'ordre
pear-dh-ini2xml: opdracht niet gevonden
pear-dh-ini2xml: parancs nem található
pear-dh-ini2xml: perintah tidak ditemukan
pear-dh-ini2xml: príkaz nenájdený
pear-dh-ini2xml: příkaz nenalezen
pear-dh-ini2xml: команда не найдена
pear-dh-ini2xml: командата не е открита
pear-dh-ini2xml: 命令找不到
pear-dh-ini2xml: コマンドが見つかりません