If you’re in Athens, this might be interest to you in planning your activities on Monday and Tuesday:

Kathimerini

Athens metro employees walked off the job for a fourth consecutive day on Sunday in protest at planned reductions to their wages, and will continue their action, together with the tram and the Piraeus-Kifissia electric railway (ISAP).
The metro, tram and ISAP will only run from 8 a.m. to 4 p.m. on Monday.
On Tuesday, they will be halting services from noon to 4 p.m.