I don't think it's that confusing, that's exactly what they're saying.

LP's from credit card spend count based on the date they're posted to your AA account each month, not the date of each individual charge. All other LP transactions count based on the date of the individual transaction (flights, hotels, eShopping, etc.).

In order for any credit card spend to count for the current qualifying year, it needs to post to your AA account before 2/28. This will be whenever your February statement closes (or 1-2 days after when it posts to AA).

So if your statement closes on the 15th of each month, you need to make sure any charges are included on the 2/15 statement if you want the LP's to count for this year. Otherwise any charges later in Feb. will post to the 3/15 statement and count towards next year's qualification.