  The Hunting Outbursting Young Stars (HOYS) project performs long-term,
optical, multi-filter, high cadence monitoring of 25 nearby young clusters and
star forming regions. Utilising Gaia DR3 data we have identified about 17000
potential young stellar members in 45 coherent astrometric groups in these
fields. Twenty one of them are clear young groups or clusters of stars within
one kiloparsec and they contain 9143 Gaia selected potential members. The
cluster distances, proper motions and membership numbers are determined. We
analyse long term (about 7yr) V, R, and I-band light curves from HOYS for 1687
of the potential cluster members. One quarter of the stars are variable in all
three optical filters, and two thirds of these have light curves that are
symmetric around the mean. Light curves affected by obscuration from
circumstellar materials are more common than those affected by accretion
bursts, by a factor of 2-4. The variability fraction in the clusters ranges
from 10 to almost 100 percent, and correlates positively with the fraction of
stars with detectable inner disks, indicating that a lot of variability is
driven by the disk. About one in six variables shows detectable periodicity,
mostly caused by magnetic spots. Two thirds of the periodic variables with disk
excess emission are slow rotators, and amongst the stars without disk excess
two thirds are fast rotators - in agreement with rotation being slowed down by
the presence of a disk.
