Milk extraction question 🚨

Hello everyone... I’m going back to work soon and I want to tell my boss that I need time to pump to keep my milk supply high... My baby is 2 months old and will be at a day care near me and I will try to manage to go there in my lunch break to breastfeed.

But the real question here is, how long do I need to pump? How many minutes or how many times a day... I’m a teacher and I know its going to be difficult. 😔

Thanks in advance!