I quickly dipped into the game this evening, (well, you have too once you see it's unexpectedly open, don't you...) and was immediately given the firefly quest. IIRC, the quest was to fill a jar (seven fireflies). I tried for a little while, and got up to six, but I don't believe I ever got beyond that.
Anyway, I then stopped playing for a little while and just returned briefly to the game now (it's time for bed really, but I just thought I'd take a quick look around...) and was greeted by the cock crowing announcing the new day - the calendar presumably ticked over whilst I was away.
In the new day summary screen, it announced that I had completed a quest during the previous day - the firefly quest. Now, I'm pretty sure I didn't complete this quest, or at least if I did, it was far from obvious to me at the time. (I've currently got five in the jar)