Assuming you've already met your 'number', and you're just trying to logically maximize the value of your final partial-year of working without considering emotion/personal-preference, then ...
I calculated the cumulative delta to my net-worth for each day of the year.
"If I work Jan1-Jan1, I'll increase my NW by $Y."
"If I work Jan1-Jan2, I'll increase my NW by $Y+"
" ... "
"If I work Jan1-Dec31, I'll increase my NW by $Y++++"
For the income half of the equation, this requires knowing things like your base-salary, bonus amounts and dates, stock amounts and vest-dates, vacation accrual-rates and payout-rates, 401k/mega-backdoor contribution rates and matching, employee-stock-purchase dates and rates, etc. For the expense half of the equation it involves any planned lifestyle/spending changes, income tax approximations, and the cost of ACA/Cobra for the remainder of the year.
Lay all that out in a spreadsheet (or approximate it as much as you like), and you'll be able to say "if I work to X date, I'll increase my stash by Y dollars". Of course Y is almost certainly the greatest if you work the whole year. That's pretty obvious and we didn't need to do the spreadsheet/graph work to figure that out.
What we're actually solving for here is the derivative. At what point(s) in the year is the rate-of-change of Y the greatest? (NB: You could view this as a second derivative if you like, since Y is already a rate-of-change.)
This will probably lead you to the intuitive conclusion that it's most dollar-for-time efficient to retire after some bonus/stock event. If you've modeled the ACA/Cobra- and lifestyle-costs well, then it'll have accounted for those aspects as well.
For me, I get the largest bonuses at end-of-Feb and mid-Sept.
End-of-Feb would be the maximal/most-efficient for me, since I'd pay relatively less in taxes, and I'd not have paid much of our employer-health-plan's deductible (switching health-plans mid-year restarts the deductible/co-pays unfortunately).
However, even armed with that knowledge ... I'm still human and I think I'm likely to 6-more-month it to mid-September. Somehow, irrationally, going from an initial 3.0% WR to a 2.75% WR feels good. Allowing more time for the pandemic to resolve without tanking the economy feels good. Cobra'ing to the end of the year would be feasible. Retiring into the fall/winter feels like a good way to quietly chill out and decompress. The only part that doesn't feel good is the actual working. ;^)