[smileybarry]

>> Employees must complete and sign Section 1 of Form I-9 no later than the first day of employment, but not before accepting a job offer.

> Looks like its any time up to the first day of work, however the wording is a little confusing. How can you start work without accepting a job offer?

It doesn't sound that confusing to me. You accept the job on date X and agree to start work on date Y; between X and Y+1, you must fill in this part of the form.

It's not uncommon to have a gap between accepting a job and starting it (in tech, at least), that's what I did as I wanted to take some time off between jobs.