To install NTP on an old debian machine, issue the following commands into the command prompt.
wget http://mirrors.mit.edu/gnewsense/gnewsense-parkes/gnewsense/pool/main/n/ntp/ntpdate_4.2.4p4+dfsg-8lenny3_amd64.deb
dpkg -i ntpdate_4.2.4p4+dfsg-8lenny3_amd64.deb
ntpdate -b europe.pool.ntp.org