It is mandau, from the carving in its sheath and handle, i guess it made by Dayak Kenyah or Dayak Wahau (a kind of Dayak tribe in Borneo).....
Sheath in Dayak term called as Kumpang..
Dayak kenyah mostly inhabit in East Kalimantan, Dayak Wahau only in East Kalimantan. But i am pretty sure that it made in East Kalimantan (Indonesian part of Borneo).
I can't predict when it made since until today they still make that kind of Mandau, the old one used to made by kind of tamahagane (they make their own steel/iron from iron sand). The grain or texture of the blade will be different from the new one which is usually made from spring steel or chainsaw bar. If it made from spring steel or chainsaw bar, i guess no more than 50 years.