u/sword-n-sorcery

I'm nearing the completion of my undergrad and I have a full-time internship lined up for the summer spanning between early June and mid-August. I'm taking a gap year before entering a Masters program in Library Science. My plan is to hopefully have a part-time Library Assistant position that I could immediately jump into after my internship ends so I could accumulate more work experience during that gap year. I was wondering whether it would be better to start applying for positions now or wait until the internship is about to end. Or is it all dependent on the job posting? And I should just watch carefully for what the posting says. Sorry if this is a dumb question.