Just my 2 cents... when we applied for preapproval, we were told we could only use dh's part time income if it was over 2 years. DH had been in paramedic/fire school, and has been breaking into a very competetive field, where most people start out pt. He now has 4 part time jobs, but we could only use 2 of them-- one VERY part time, and another that he started 18 months ago (they allowed even though not 24 months). We could not use his primary income since it was only 8 months, or a brand new job, even with a letter from the employer.
It was so frustrating because had dh NOT left his long-time restaurant job, we could have used that income, but of course, these were better career choices. One lender who rejected us actually suggested that dh get a full time job at the local gas station, so we could include that income... and do what? Leave one of the jobs he worked so hard to get, or work 100 hours a week instead of the 60 hours???
Anyway, it ended up working out for us eventually....