  We consider the algorithmic complexity of recognizing bipartite temporal
graphs. Rather than defining these graphs solely by their underlying graph or
individual layers, we define a bipartite temporal graph as one in which every
layer can be 2-colored in a way that results in few changes between any two
consecutive layers. This approach follows the framework of multistage problems
that has received a growing amount of attention in recent years. We investigate
the complexity of recognizing these graphs. We show that this problem is
NP-hard even if there are only two layers or if only one change is allowed
between consecutive layers. We consider the parameterized complexity of the
problem with respect to several structural graph parameters, which we transfer
from the static to the temporal setting in three different ways. Finally, we
consider a version of the problem in which we only restrict the total number of
changes throughout the lifetime of the graph. We show that this variant is
fixed-parameter tractable with respect to the number of changes.
