Hi Nirvan,
This has been discussed before in similar posts as it is one of the famous issues in JSF, the problem is in time zone.
By default JSF uses GMT timezone to convert the date into display format, however you can change this behavior is several ways, one is to specify explicitly the timeZone attribute in the f:convertDateTime tag. Two is you can create a custom date converter as suggested in this post
date problem. Three if you are using JSF 2 you can apply a global settings for the time zone by adding a context param in the web xml. the context param name is javax.faces.DATETIMECONVERTER_DEFAULT_TIMEZONE_IS_SYSTEM_TIMEZONE and you can set it to true, this will cause the datetimeconverter to use the default system time zone instead. Hope this can help