  We search for ultralight scalar dark matter candidates that induce
oscillations of the fine structure constant, the electron and quark masses, and
the quantum chromodynamics energy scale with frequency comparison data between
an $^{171}$Yb optical lattice clock and a $^{133}$Cs fountain microwave clock
that span 298 days with an uptime of 15.4 $\%$. New limits on the couplings of
the scalar dark matter to electrons and gluons in the mass range from
$10^{-22}$ eV/$c^{2}$ to $10^{-20}$ eV/$c^{2}$ are set, assuming that each of
these couplings is the dominant source of the modulation in the frequency
ratio. The absolute frequency of the $^{171}$Yb clock transition is also
determined as $518\,295\,836\,590\,863.69(28)$ Hz, which is one of the
important contributions towards a redefinition of the SI second.
