  The HERMES-TP/SP (High Energy Rapid Modular Ensemble of Satellites --
Technologic and Scientific Pathfinder) is an in-orbit demonstration of the
so-called distributed astronomy concept. Conceived as a mini-constellation of
six 3U nano-satellites hosting a new miniaturized detector, HERMES-TP/SP aims
at the detection and accurate localisation of bright high-energy transients
such as Gamma-Ray Bursts. The large energy band, the excellent temporal
resolution and the wide field of view that characterize the detectors of the
constellation represent the key features for the next generation high-energy
all-sky monitor with good localisation capabilities that will play a pivotal
role in the future of Multi-messenger Astronomy. In this work, we will describe
in detail the temporal techniques that allow the localisation of bright
transient events taking advantage of their almost simultaneous observation by
spatially spaced detectors. Moreover, we will quantitatively discuss the
all-sky monitor capabilities of the HERMES Pathfinder as well as its achievable
accuracies on the localisation of the detected Gamma-Ray Bursts.
