Nowadays most interviewers understand that the new generation of jobseekers don't necessarily hunt for jobs right after graduating, in fact if you took the time out to do some traveling, volunteering, working in part time jobs, helping out the family, etc it will give you an added advantage because it shows you have more life experiences compared to a freshie who hunts for a job right away.
So if you have a solid reason and used your time off wisely, the interviewer should be able to appreciate that. Dont worry!
(I took 7 months off from my first job and landed my second easily)