Babysitter Needed For 2 Children

Seeking a babysitter for 2 children. I am in real estate, my schedule is flexible and varies from week to week. During the school year, will be one child some Tues/Thurs and both children some Sat/Sun but schedule will vary per week. Willing to pay more for an 'on call' sitter or minimum hours per week since my schedule varies. Need someone who is reliable, flexible with my schedule, and willing to come to my home. I will need someone available during the hours 8-5pm, but not for that entire period of time.