... we're off-contract during the summer. Most of us. That means, strictly speaking, we're not getting paid to work. You may come across a faculty member in a campus office during the summer for a variety of reasons: 1) they may be teaching a summer course, in which case they are getting paid just to teach that course, not do advising or mentoring you through your thesis, or 2) they may have "days" paid from a grant, in which case they are there to work on grant-related activities only, again, not just hang out and do advising with you (unless that's one of the grant-related activities). or 3) they have extensive service obligations to the university (like department responsibilities or Faculty Senate meetings) and again, it's not time to hang out with you. The other reasons we may be up there is to write and do our research and try to weed through all the papers that have piled up over the year and try to sort through the mess before the next academic year starts back up.
So if you absolutely MUST drop-dead HAVE to talk to me ... send me an email at least a week in advance and give me options of days and times we can meet. I'm working around other meeting times, plus my kids are now getting out of school and now I have to work with their schedules. Strictly speaking, though, I'm doing you a favor. Oh ... and call me Dr., really. I am not your new best friend. Do not call me by my first name, especially not when I'm giving up my summer break to meet with you. And don't get uppity if I don't respond immediately. IT'S MY SUMMER BREAK, BRO.