Yes, i believe Nibiru will block out the sun for 3 days as testified from the Biblical event (Plagues of Egypt), to the future prophecy of the 3 days of darkness. It also says,

"I will make the sun go down at noon time."

The Sun going "down" is NOT the same as going dark.
This points to the poll shift that will happen when Nibiru passes by. Which in turn, create the "New Heaven(s)."

The "new Earth" may rise from the sea and/or potentially shift Greenland and Northern Canada further down toward the Equator. This will change and warm up their climates make human habitation more likely in those areas.