  A long-standing problem when deriving the physical properties of stellar
populations is the degeneracy between age, reddening, and metallicity. When a
single metallicity is used for all star clusters in a galaxy, this degeneracy
can result in $`$catastrophic$'$ errors for old globular clusters. Typically,
approximately 10 - 20 % of all clusters detected in spiral galaxies can have
ages that are incorrect by a factor of ten or more. In this paper we present a
pilot study for four galaxies (NGC 628, NGC 1433, NGC 1365, and NGC 3351) from
the PHANGS-HST survey. We describe methods to correct the age-dating for old
globular clusters, by first identifying candidates using their colors, and then
reassigning ages and reddening based on a lower metallicity solution. We find
that young $`$interlopers$'$ can be identified from their Halpha flux. CO (2-1)
intensity or the presence of dust can also be used, but our tests show that
they do not work as well. Improvements in the success fraction are possible at
the $\sim$ 15 % level (reducing the fraction of catastrophic age-estimates from
between 13 - 21 % to 3 - 8 %). A large fraction of the incorrectly age-dated
globular clusters are systematically given ages around 100 Myr, polluting the
younger populations as well. Incorrectly age-dated globular clusters
significantly impact the observed cluster age distribution in NGC 628, which
affects the physical interpretation of cluster disruption in this galaxy. For
NGC 1365, we also demonstrate how to fix a second major age-dating problem,
where very dusty young clusters with E(B-V) $>$ 1.5 mag are assigned old,
globular-cluster like ages. Finally, we note the discovery of a dense
population of $\sim$ 300 Myr clusters around the central region of NGC 1365.
and discuss how this results naturally from the dynamics in a barred galaxy.
