Research has long suggested that significantly increasing quality time in school for teaching and learning can have a positive impact on student achievement. Recognizing this connection, federal guidance requires low-performing schools to increase student learning time if they are implementing two popular reform models using school improvement grant (SIG) funds appropriated by the American Reinvestment and Recovery Act (ARRA). This special report by the Center on Education Policy (CEP) highlights findings about this increased learning time requirement from two recent CEP studies of SIG implementation in school year 2010-11 and the fall and winter of 2011-12. The first study was based on a CEP survey of state education officials in 46 responding states, including the District of Columbia. The second consisted of in-depth case studies of state and local SIG implementation in Maryland, Michigan, and Idaho. Key findings include the following: (1) All 46 states responding to CEP's survey reported that at least some of their SIG-funded schools are implementing one of two federal school improvement models that require increased learning time; (2) Officials in a majority of the states surveyed said the strategy of increasing learning time is, to a great extent or some extent, a key element in improving achievement in SIG-funded schools; (3) All three case study states have ensured that schools using the transformation or turnaround models are increasing learning time, but the degree of state focus on this strategy varies; and (4) All SIG-funded case study schools that are using the transformation or turnaround models have increased students' learning time, as have some non-funded schools, but implementation and emphasis varied. (Contains 1 table and 1 box.) [For related reports, see "Schools with Federal Improvement Grants Face Challenges in Replacing Principals and Teachers" (ED533563) and "Changing the School Climate Is the First Step to Reform in Many Schools with Federal Improvement Grants" (ED533561).]