If I earn R40k pm for 5 months is it anualised for tax purposes and tax liability apportioned 5/12?

If I earn R40,000 per month and only work for 5 months(R200,000) of Tax Year(say 28 Feb 2016), is tax computed on R40k X 12 ie R480k and Tax liability apportioned 5/12ths or on R40k x 5 ie R200k and tax liability only on R200k for full year?

It is calculated as if you worked a full year which means you should be due a significant refund.