I know we can do the dungeons once a day but do the reset at the end of that day? for example I got to the last boss of the dungeon but could not defeat him. will I still be at the boss tomorrow or will I start at the beginning?

@Rosedawn

Dungeons reset every day at 12:00AM server time. If you have not finished your dungeon by that point, you will then have the option of resetting the dungeon if you choose.

So if you are stuck at a certain spot and can't continue, you can wait until after the daily reset goes and then manually reset your dungeon to start over.

I hope that answers your question. Let me know if you have any others!