Dear friend,
Don't afraid. It is your employer's responisblity to award that one as you have completed 4 years + 240 days. In 5th year completion of 240 days can be considered as completion of one year. In such type of dispute, all the judgements have been awarded in favour of employee. Incompletion of remaining one month can't cease your gratitude period.
You don't need beg your HR to extend the staying period upto completion of of 5 years. It is your right friend.
Bai,
Sathish