definiens: means an amount ( n ot less than zero ) equal to the aggregate current Income Tax liabilities of Purchaser and its Subsidi aries ( other than the Conveyed Subsidiaries and the ir Subsidiaries ) ( which shall not be less than zero in any jurisdiction ) for all taxable periods ( or port ions thereof ) ending on or before the Closing Date for which fina l Tax Returns have not been filed . The calculation of Purchaser Accrued Income Taxes shall ( i ) exclude an y deferred Tax liabilities or deferred Tax assets a nd any amounts in respect of speculative or contingent lia bilities for Tax, ( ii ) include estimated ( or other prepaid ) Income Tax payments only to the extent that such pa yments have the effect of reducing ( not below zero ) the particular current Income Tax liability in respect of which such payments were made, ( iii ) include Inc ome Tax deductions or Tax refunds ( including for overpaymen ts of estimated Taxes ), in each case, only to the e xtent such deductions or Tax refunds have the effect of reduci ng ( not below zero ) a particular current Income Tax liability to which they are relevant, ( iv ) be prepared in acc ordance with the past practice ( including reporting positions and accounting methods ) of Purchaser or its applica ble Subsidiary in preparing Tax Returns for Income Taxes and ( v ) in the case of a Straddle Period, be determ ined in accordance with Section 6.5(d)(iii )