You can only get the LF if the adventure is not exhausted when you run it. Adventures reset at midnight GMT, but don't update their status until you refresh your browser. Ordinarily you can get it once before reset, and again after reset by refreshing your browser. Since the LF moves on a 25 hour schedule, it is also possible to get it 3 times a day. You have to have logged in on the previous "game" day and get it the first time, refresh to get it the second, refresh again after reset and get it the third time before it moves to a new location. Triple dipping is easiest when the LF moves soon after daily reset.
You can manage two or three times per day if you take advantage of the fact that the adventures reset at 00:00 UTC every day. Edit: I have been vezaninjaed.
