A slight issue I have with the idea of the second movie taking place very shortly after the first is the spiketail hatchling Spike meets during the credits. It’s entirely possible that the filmmakers forgot (or just didn’t know) that Spike had been a hatchling himself in the first movie. Alternatively, we could assume it to belong to a pygmy species of stegosaur (something like a spiketail version of the tinysauruses, but bigger). Or maybe that spiketail had simply not experienced the same growth spurt as Spike immediately after hatching.

Also, at the end of LBT IV, we appear to see Littlefoot’s grandpa standing up and walking for the first time after recovering from his illness
after Ali’s herd leaves. Given the incredible healing properties of the night flowers (Grandpa Longneck had barely swallowed them before opening his eyes and declaring that he was feeling better :blink:), I doubt much time had passed between the gang’s return and Ali’s departure.
As far as temporal conundrums
within (as opposed to between) the LBT films are concerned, the amount of time the gang took to reach the Great Valley in the first movie is definitely a biggie. If we were to make an estimate based merely on the number of days and nights shown in the film, it would appear to be only a few days; I seriously doubt the trip was actually that short. My guess is a couple of weeks at least.
Another imponderable is the time it took for the Great Valley to dry up in LBT III. Blind observation (how’s that for a contradiction in terms?

) would indicate that the meeting between the adults at which Littlefoot was accused of wasting water took place on the same day the Thundering Falls stopped. This certainly couldn’t have been the case. I know little about droughts, but I would expect that it would take several days at least for the water level in the big river to drop noticeably, let alone for the tree stars (however hydrophilic they may be) to dry up. Only three or four nights are explicitly indicated to have passed in the entire movie, so, as with the first film, we can really only guess at how much time has elapsed.
One hypothesis of mine concerning the rapid regrowth of the Great Valley’s vegetation is that the soil in the Valley is unusually fertile due to the area being very volcanically active (as evidenced by the frequent earthshakes, smoking mountains, and abundant hot springs, tar pits, and volcanic mud pools both inside and outside the Valley). Of course, even with this excuse, the Great Valley’s flora should realistically take quite some time to recover from the fire in LBT III (especially as far as the trees are concerned), but as we all know, LBT has an elastic sense of realism.
