As per the provision of AS-15 company need to get the valuation done for the gratuity on balance sheet that is 31.03.2019 , in case any employee left on 15th march 2019 ,that employee should also be considered for the l employee data to be shared with actuarial as on 31.03.2019 and liability to be created as on 31.03.2019 will covered that employee liability for the current year.