Babysitter Needed for my Children

My husband and I are looking to hire a nanny/baby-sitter for our 2. 5-year-old son for a monthly date night. We're hoping to find 1 - 3 baby sitters that we can rotate between, depending on their availability, for a monthly parents' night out that our son trusts and has fun with. We would need between 3 - 4 hours on a Thursday or Friday and would only travel locally. We are flexible on the specific date and time so we're looking for someone who is interested in developing a long term yet temporary/flexible care relationship. About us: we're a professional couple that live in San Rafael. We've lived in Marin County for about 5 years and are originally from the Central Valley.