Startup Idea: Employee Scheduling Software for YMCA

Startup idea to develop an employee scheduling software for the YMCA. The software should facilitate shift management for 25 employees considering their preferred work days and off days while avoiding certain days or shifts. Should also help in tracking actual workdays and complex scheduling scenarios.

I work as a scheduler for the YMCA. I have 25 employees each of which work various shifts, and need various days off. It is difficult to ensure that I get employees the number of days they prefer to work (more than X, less than Y), and that they do not work any days or shifts that they don't want to work. I have tried using Excel to do this but it gets too complicated, since I need to track which days are actual workdays (no Sundays, no Saturday evenings).