Research has revealed that students' alertness and attentiveness are affected by time of day preferences. A review of relevant literature indicated that preferences are significant in predicting performance levels for school children, and that matching students with peak times is not only beneficial for academic subjects, but also influences discipline and test-taking. Teachers are also shown to have ideal times of day that may affect their teaching abilities. The purpose of this study was to find out how time of day affects student attention and achievement. Fifth-grade students (n=36) in a small, rural school in Virginia, were given Learning Styles Inventories (LSIs) in order to assess their personal preference for time of day. Then, they were taught and tested using scripted laser disk science lessons in both morning and afternoon situations. The goal of this project was to determine if students had high levels of attention and achievement when taught at times that coincided with their time of day preferences as indicated on LSIs. The results suggested that time of day played a role in student achievement. Students taught at times that matched their learning style preferences scored significantly higher on lesson-related quizzes. Students also scored better on average at their teacher's ideal time of day. The study also indicated that the majority of students can accurately predict their preferred time of day. The study illustrated that time of day should be considered as teachers plan and implement lessons. Appendixes include: science lesson-related quizzes; the morning/afternoon preference survey; learning styles inventory; and off-task seating charts. (Contains 24 references.) (ND)