No-brainer.
Open House only. At most you need to do sai kang. And even then,
you can bring your medical status slips to excuse yourself from
heavy sai kang.
As was mentioned by the previous poster, ignore this callup at
your own peril.
Sir, you literally mean it's an open house and he is doing sai
kang there, or it's jargon fo going & doing shit for one day?
cos all my years i've never heard this jargon.