I've got them at 0034 UTC, 31 MAR (Wednesday the 30th still here in N. America) with a good signal.
Try these emails - you may get an answer, but I've gotten nothing when I wrote to implore them to stay on the air.
ertinternational@ert.gr
thevoiceofgreece@ert.gr
It used to be this email, where I got my QSL from several years ago (2017 or so), but it's a personal email and I'm not sure it's still valid.
dgazidellis@ert.gr