World cruise segment shore excursion release dates and overnight land excursions question

[Murphy]

We are booked on the Miami to Singapore 77 night portion of the 2025 Insignia ATW cruise.  On a longer cruise like this, are all the excursions for the full cruise released 365 days out from the initial sail date, or is it more like 365 days from the actual port day?

 

Also, I've read that overnight land excursions aren't handled like an excursion, but need to be booked differently.  I'm hoping we are able to do an overnight safari during part of the African segments.  Any feedback on how these work would be appreciated.  This will be our 1st Oceania cruise and by far the longest sailing we've done, however we have sailed over 30 days a few times...  TIA