Hi Rajesh,
Your crystal oscillator is always going to have an error rate which is probably going to be unacceptable. The only way to get rid of this accumulated error is to slave your clock to a known reference such as the power utility or an atomic clock. The following web site tells how to modify a cheap 60 kHz radio signal to attain super accuracy. The same thing could be done with whatever is available where you are located on the planet.
http://www.amug.org/~jthomas/wwvb.html
Regards,
Charles Bannister