mactime: 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
/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/mactime - from package: sleuthkit

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