Uhhh, I don't want to argue with those instructions, and yes, you understand them correctly.
But I suspect you will have stable gravity on Day 4-5, meaning primary fermentation is done, so after an equal amount of time (4-5 days perhaps) your diacetyl rest is finished and the beer can be packaged.
OK, it won't hurt to stretch that to 14 days... but 28 days seems... long. Longer than necessary, imho. I have never had an ale go longer than 10-12 days.
Your Tilt will tell you when gravity is stable. Don't believe the number it gives you, but believe that it isn't changing. At that point, it is half done. Dry hop it the second time, wait the equal time, then bottle it.
That's my opinion. It is worthless, but you got it for free anyway. Let us know how it turns out!