This study uses a newly compiled data set of instructional time and student performance by subject across German federal states for student cohorts enrolled at the primary level in the 1990s and tested at the secondary level in the 2000s. It finds evidence for the school inputs-student achievement relationship, taking nonlinearity, cross-discipline and cross-academic progress effects into account, on the basis of regression models with state fixed effects. We find that high school ninth graders benefit from lifetime instructional time, in particular at the pre-secondary level. The results accommodate self-productivity, dynamic complementarity, and depreciation.