In my experience this is legal but can be very hard to book. united.com will sometimes, but not always, show this kind of booking as available online, apparently depending on the current time of day?!!?

What I found when trying to book a similar connection (BOS-SFO arriving too late for any connection that night, SFO-LAX first available flight in the morning) was that:

• A week in advance, multiple phone agents insisted that this was not a legal connection, even though united.com showed that kind of routing available as an award booking for (say) that very night.
• On the day of travel, **after all other available flights BOS-SFO had departed**, united.com finally consented to show BOS-SFO/overnight/SFO-LAX as an available award for booking as a one-way trip BOS-LAX at the one-way Saver price.
• When I called to book it (in transit, flaky Internet connection), a phone agent saw the award, built it, then "did me a favor" without my asking and changed the connection in the morning to a later flight on a 777.
• That was pretty thoughtful since I was booking a saver F award and this meant 777 C instead of domestic F… but then the award never ticketed, and I showed up at the airport an hour later for the flight and was told "you have no ticket", and when I called a phone agent to ask them to forcibly ticket it, I discovered after travel that I had been charged 50,000 miles instead of the quoted 25,000. A PM to UA Insider led to a promise that they'd investigate & fix it, but I never heard back afterwards.

It **should** be a legal connection on an award ticket for you to fly NYC-LAX // LAX-OGG even if you have >4 hours if it's the next available flight.

However, "should" and "an actual human will consent to book it" are very different worlds. When I tried to do something similar (BOS-SFO/overnight/SFO-LAX), before the magic time of day when united.com started showing this award as a valid routing, I had phone agents make up all kinds of excuses why it wasn't a legal connection.