Now what you have cited , the 4 years and 240 days or half fraction yielding to more than 6 months, is only taken into considerations for the payment and calculation of Gratuity.
240 days in the last year is only taken into consideration , if you are in the jurisdiction of Tamil Nadu.
Now it rest on the employers wish, few employers consider the 240 days in last year, and few don't.., as the verdict was given my Madras High Court, and its binding upon Tamil Nadu region employees. So Legally, if you are not from T.Nadu region , your employer can well decline in giving you the Gratuity Benefits unless you serve a complete 5 years employment service.
17th April 2012 From India, Calcutta
17th April 2012 From India, Gurgaon