  Large-scale social networks constructed using contact metadata have been
invaluable tools for understanding and testing social theories of society-wide
social structures. However, multiplex relationships explaining different social
contexts have been out of reach of this methodology, limiting our ability to
understand this crucial aspect of social systems. We propose a method that
infers latent social times from the weekly activity of large-scale contact
metadata, and reconstruct multilayer networks where layers correspond to social
times. We then analyze the temporal multiplexity of ties in a society-wide
communication network of millions of individuals. This allows us to test the
propositions of Feld's social focus theory across a society-wide network: We
show that ties favour their own social times regardless of contact intensity,
suggesting they reflect underlying social foci. We present a result on strength
of monoplex ties, which indicates that monoplex ties are bridging and even more
important for global network connectivity than the weak, low-contact ties.
Finally, we show that social times are transitive, so that when egos use a
social time for a small subset of alters, the alters use the social time among
themselves as well. Our framework opens up a way to analyse large-scale
communication as multiplex networks and uncovers society-level patterns of
multiplex connectivity.
