All Nippon Airways Mileage Club - BKK-NRT & NRT-LAX award availability

I have a Star Alliance C award through UA for a trip in late Nov/early Dec from LAX to NRT/BKK. I am trying to change the dates on the return BKK-NRT and NRT-LAX legs but see hardly any C availibility on either sector for the first week of Dec. Does NH have a tendency to release award seats in C at the last minute? A few days, weeks, months out? I'm checking the ANA award tool everyday but so far no luck.

I'm checking the ANA award tool everyday but so far no luck.

You know better UA has starnet blocking, other than checking ANA tool everyday, I suggest you also call UA award desk everyday. If any seats pop up, you still have to call them and change anyway.