Hi,
Could someone Please clarify me here:

Is ntpdate command a part of ntpd, i mean does ntpdate command a dependent on ntpd? and can ntpdate be run in absence of ntpd service.

• ntpdate is a seperate utility, complimentary to ntpdate
• ntpdate is not directly dependant on ntpd; but it does require a time service
• yes, ntpdate can be run without ntpd; but you need to point it to a time service. There are many public available (free) ones.

OBTW, I forgot to mention, one of the most common uses of ntpdate is in the root crontab file, for example:

10 2 * * * /usr/sbin/ntpdate time.nist.gov > /dev/null 2>&1

root@myhost:~# ntpdate time.nist.gov 
 4 Dec 07:33:58 ntpdate[12496]: step time server 128.138.141.172 offset -17.447227 sec

The pool.ntp.org project is a big virtual cluster of timeservers providing reliable easy to use NTP service for millions of clients. The pool is being used by millions or tens of millions of systems around the world. It's the default "time server" for most of the major Linux distributions and many networked appliances (see information for vendors).

Thanks Neo for your answer!!
for my better understnding , could you please list few of the time services which can support ntpdate command and are very commonly and frequently used.