Advertise as a monthly guaranteed wage - so determine how many hours you want to reserve each month and how much you are paying per hour and that will be paid to the nanny no matter what, even if you don’t use them all.

You might find someone who has a flexible schedule as long as you can guarantee their monthly pay.

I worked pt for a while (ended up going full time) and the days fluctuated weekly. I was given my schedule at least a week in advance, sometimes later, but they told me as soon as they found out. You are definitely going to have to offer competitive pay. I had gaurenteed 30 hours and anything after 30 they paid time and half (1st perk). I recieved 6 paid vacations and 5 sick days (2nd perk).