APIv2:/achievements/daily and APIv2:/achievements/daily/tomorrow actually miss lot of informations.
I know that actually you are working hard on API, and that API is not fully back to its power, but for when it will happen I have a suggestion to discuss with you about the two endpoints above.
From in-game menu we have lot of categories in Daily group, but the the mentioned endpoints return only pve, pvp, wvw, fractals, and special; all as Object.
Hoping that you will integrate all the Dailies, I have a question: why these two endpoints don't return any ID!?
All other endpoints that don't require authentication return them, I don't understand why in these cases there aren't string ID like "id":"pvp", "id":"pve","id": "wvw", "id":"fractals", "id":"special" and so on, instead of object called with those names.
Considering that you sometimes add new Daily categories I think that uniform these endpoints to the others would be the best choice.