New grad got hired but have a question

[sourapril]

So I just got a call from a nursing home I applied 1 week ago and they offered me a full time CNA position. It's day shift M-F and every other weekend. They want me to start next Monday at 8am. But here is my situation: I have been working for this home care agency for less than a month. I work part time a couple of hours in the morning. I love my clients and the company has been very nice to me. I don't really want to quit my part time job. I will ask them if they can change my shift so that I can do both jobs. But I only have Friday and this weekend to tell them. I also get paid this Friday. Would that be too short a notice? I am sure they can find someone to cover my shift. I just want to be courteous. How should I and when should I tell them? Thanks!