I found out that when you get the "fire in the skies" daily, you can get on the firebird, bomb/hit the rare elemental for the achievement, return to the front and leave your unfinished quest in ur logs. Come back after 2 a.m. (I play central time on Azgalor) and the firebird will not be there. Drop your quest, get the new daily and complete it. On the following day, you will get the "fire in the skies" daily again since you didn't actually do it yest. I've tried it twice and both times it has worked for me!!
P.S. Dailies reset at 4 a.m. on my realm.