I've been paying attention and wondering about this because we're in this same situation for a Feb trip for our 2 kids that are aged 11 and 8 and got their second shot in December. As others have said, it's frustrating to try to find information because I've read about 10 different articles from different sources that all essentially repeat the same information from the Governor's quote from last week.
I read somewhere in Maui's order the official language was that you had to have at least 2 shots and the most recent within 5 months. The idea for the booster is that your immunity has faded after that 5-6 month period of time. It seems like quite a logistical headache down the road to start counting shots when further boosters may be required. Will there come a point where if you've never had a shot, you can't come to Hawaii until you've gotten 4 or 5? How would you ever get caught up 2 or 3 years from now if you were just starting the vaccinations? Surely it will just be most recent in last 5 months.