The "Longer School Day" could be administered in the following way;
Start time 7:00 - 8:30
Programs offered: 45 minutes Performing Arts + 45 min Skills Gap Tutorial
Performing Arts Courses Offered - Musical Theatre, Jazz Dance, Visual Arts, Orchestra or Band
Skill Gap Course - Taught by College Students who major in Education (Reading or Math) as an internship
Weak Readers - Phonics drills and decoding small narratives. How to respond to a writing prompts would also be done in exercises.
Strong Readers - Discussion groups to pull out and discuss key elements of the story. Organizing a response to writing prompts. How to write a response that would receive a top score on a standardized exam by reviewing sample essays and doing practice work.
Students behind in Math - Tutor would be teaching Basic Math (Addition, Subtract, Multiplication, Division, Fractions and introduce percents. How to decode a simple word problem that has multiple steps, review of basic math vocabulary, rules and properties. How to check your work should be covered.
Average Students - Review basic skills to address any skill gaps, focus then on decoding word problems. Algebra basics. Work out problems by hand and only using a calculator to check work. Review of math vocabulary, rules and properties.
Above Average Students - Assess their skills, address any concerns and do higher level math problem solving, discreet and linear math and probabilities. (School counselors could match them up with Saturday programs that will also challenge them as well.)
These tutorial would also have a break time!
Hopes this suggestion is useful.