definiens: means, with respect to a particular Collaboration Target, ( a ) with respect123 to the frrst Contract Year, the'period beginning on the date such Collaboration Target is accepted into the124 Collaboration ( or,'in the case of the first Collaboration Target, the Effective Date ) and ending on Decem-125 ber 3 - 1of the calendar year in which such acceptance takes place ( or, in the case of the first Collaboration126 T'!1'get, December 31,2006 ) ( such period, the ), ! and ( b ) with respect to each subse-127 quent Contract Year, ihe twelve ( 12 ) month period beginning on'ih'e ~ ay follnwing the end of the First128 Contract Year and each succeeding twelve ( 12 ) month period thereafter . Each Contract Year ( other than129 ' the First and last Contract Year ;, as applicable ) shall be divided into four ( 4 ) com-130 prised of successive three ( 3 ) month periods . In the First Contract Year, the fir;t Contract Quarter shall131 begin on the fir;t day of the Fir;t Contract Year and shall end on the last day of the calendar quarter in132 which the relevant Collaboration Target is accepted into the Collaboration ( or, in the case of the flr ; ( Col-133 laboration Target,'1une 30,2(06 ) .