The time of the event has got nothing to do with the form 'is being' in that case. The form 'is/are/was/etc. + being' means 'behaving' in some way (in the active voice; in the passive it is used to emphasise the fact that an action is happening at the moment of speaking). Cf.
1. I was at a party at 4 o'clock.
I was being hasty at the party. ACTIVE VOICE
Źle się zachowywałam na przyjęciu.
You're being awful today!
Okropnie się dzisiaj zachowujesz!
I was being interviewed by the police at 4 o'clock. PASSIVE VOICE
Byłam przesłuchiwana przez policję o godzinie 4.
A new bridge is being built in our town.
W naszym mieście jest właśnie budowany nowy most.