Does it make sense to apply for assistant professorship positions before Ph.D. graduation?
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).