It is advisable to arrange flexible/ extended childcare.
Your days/hours will vary with changes in rotation and also when you attend teaching sessions/ VTS days/ courses etc.
I for example work 60% (= 3 days per week) but have 4 days a week childcare. This is also flexible so I can arrange the days to suit me. This allows me to attend training sessions/ have some time to prepare presentations/ other work etc as on the other days of the week I have my kids and no opportunity to do any work/ preparation.
You can get childcare vouchers to pay off some of your childcare with your pre-tax earnings. Ask at your nursery and practice/medical staffing to find out which programme they are registered with. You then also register and it will take care of itself. You can be exempt of the tax on a maximum of £243 a month this way.