Does it make sense to apply for assistant professorship positions before Ph.D. graduation? In the course of browsing a couple of positions for brand-new (STEM-related) assistant professorships (in North America), I am wondering whether it does make sense if one applies for such positions before her Ph.D. graduation. For example, an advertisement asserts that

These positions require a Ph.D. or equivalent in engineering or a
closely related discipline at date of hire

The job announcement has only supplied a period for application submissions, say, Nov. 2020 until May 2021. My Ph.D. defense is around early 2021, but I think if I wait till that time, the positions may have already been occupied without any chance of competition for me. But if I act before graduation, will my potential application be considered when I have not yet sealed my Ph.D.?
Most people apply for positions while still students. That is normal. The &quot;date of hire&quot; could mean various things, depending on the institution. Don't worry too much about it, and apply. If there is any sort of issue they might be able to finesse it a bit, but likely they intend that early 2021 graduates are part of their intended outreach.
The date of hire is not usually interpreted as the date you get an acceptance letter, but the date you actually become an employee (with a paycheck).