  The Ulysses spacecraft provided the first opportunity to identify and study
Interstellar Dust (ISD) in-situ in the Solar System between 1992 and 2007. Here
we present the first comprehensive analysis of the ISD component in the entire
Ulysses dust data set. We analysed several parameters of the ISD flow in a
time-resolved fashion: flux, flow direction, mass index, and flow width. The
general picture is in agreement with a time-dependent focussing/defocussing of
the charged dust particles due to long-term variations of the solar magnetic
field throughout a solar magnetic cycle of 22 years. In addition, we confirm a
shift in dust direction of $50^{\circ} \pm 7^{\circ}$ in 2005, along with a
steep, size-dependent increase in flux by a factor of 4 within 8 months. To
date, this is difficult to interpret and has to be examined in more detail by
new dynamical simulations. This work is part of a series of three papers. This
paper concentrates on the time-dependent flux and direction of the ISD. In a
companion paper (Kr\"uger et al., 2015) we analyse the overall mass
distribution of the ISD measured by Ulysses, and a third paper discusses the
results of modelling the flow of the ISD as seen by Ulysses (Sterken et al.,
2015).
