What time is it in Bougainville?

Papua New Guinea spans 2 time zones, so the answer depends on where in it you mean. Bougainville is 1 hour ahead Port Moresby, which is the zone most people mean by “the time in Papua New Guinea”.

Bougainville does not observe daylight saving, so its offset from UTC never moves. Its relationship to places that do change shifts twice a year instead.