DST is generally not observed near the equator, where sunrise times do not vary enough to justify it. Some countries observe it only in some regions; for example, southern Brazil observes it while equatorial Brazil does not. Only a minority of the world's population uses DST because Asia and Africa generally do not observe it.
Try to answer this question if possible (otherwise reply "unanswerable"): Which part of Brazil observes Daylight Saving Time?
southern Brazil