  We perform an analysis supplementing the metrology toolbox in the
time-frequency domain. While the relevant time-frequency-based metrological
protocols can be borrowed from the spatial domain, where they have recently
been well developed, their ultimate practical usefulness is shown to be
restricted by limits put on the bandwidth of both the signal and measurements,
as well as by the finite measurement time. As we demonstrate for the well-known
problem of multiparameter estimation for two incoherent, point-like sources,
the impact of these experimental limitations on the optimal protocol's
efficiency can be detrimental. Nonetheless, we propose necessary operational
criteria for attainability of the quantum Cram\'{e}r-Rao bound under the
discussed restrictions.
