When can I book?

I'm trying to book a rewards flight to fly on June 5, 2026. I live in North Carolina, USA. When do those dates open up on the Singapore Air website? Looks like 355 days out, but I'm seeing conflicting info on their website. As of today (June 13, 2025) I only see availability up to June 1 2026 (353 days out). Anyone else seeing the same thing or know when flights are released? Any help on this would be appreciated?