I worked at the same company for 24 yrs and progressed to a supervisor role over that time. Once laid off my wife and I looked into starting a mobile medical office to the point of having a business plan and talking to partners but then other elements of her career opened up and we stopped pursuing it. I then switched to a stay-at-home father role to support her progress. How should I explain the one year gap in my resume?
For me, a gap in a resume instantly pushes it towards the reject pile - to go to the next step with gaps, it had better be a pretty good one. Never leave gaps - you might not get an interview to explain them - especially if it appears you are hiding the gaps.
As a potential employer I would value the experience a failed start up gives someone and to leave the off a resume is wrong. To me, "1 Year - Failed startup..." is a superior resume than virtually any other 1 year of experience -especially for someone with 24 years working for the same company.
At interview time, I would be asking a lot of questions around that, and would be looking to see what you learnt from the experience.
If a company rejects you for putting "Stay at home dad" on your resume, you are probably better off if they do not interview you.