Yes, it's a payroll check (to me, from me) that is already physically dated that date.  I started filling it out on that date but desktop payroll stopped working thus I didn't know the dollar amount to make it out for.  So, I sit it aside until I got transferred to QB Online, but then life got in the way and that took a month.

And yes, I totally get that post-dating payroll checks to OTHER PEOPLE is a very bad thing to do.  Completely on board with that.

But realize, that's not the case here.  I'm just a 100% commissioned independent contractor who incorporated and does payroll because lawyers, insurance vendors, accountants and the IRS wanted it that way.  Bookkeeping happens when I have free time, not because it's the 15th.  I also routinely throw my monthly payroll checks in a drawer until the business' cash flow allows me to deposit them.

But back to topic, it's my understanding from Googling this over and over again that the workaround is to enter it as "historical data" in Online but I just can't find where/how to do it because Online doesn't quite look like the pictures on the Intuit help screen.

Looks like the other solution is to just migrate back to Desktop which doesn't tell me when I did stuff.