ordinary time earnings, page-2

The ATO defines it here.

http://www.ato.gov.au/businesses/content.aspx?doc=/content/00249857.htm&page=24&H24

and here:

http://law.ato.gov.au/atolaw/view.htm?DocID=SGR/SGR20092/NAT/ATO/00001&PiT=99991231235958


Some allowances are considered to be included in ordinary time earnings which will be calculated to include SGC, but overtime is not.