Sept 2015 is wishful thinking and the projection of impatient minds.
Or these impatient minds could be right.
I doubt it.
Here's one analysis why it is unlikely to be Sept 2015.
I seem to recall that during Budget 2015, it was noted that this year's budget will incur a deficit of about $6b. And there were some programmes that have been extended to 2016 and beyond which means that the 2016 budget will also incur a deficit. But this is fine as the govt has accumulated surpluses over the last few years, and can offset the deficit with those surpluses.If there is a planned deficit for the FY2016 budget, then the GE cannot be before April 2016.
BUT, if the election is before April 2016, parliament will be dissolved and there would be a new government (new parliament) in FY2016, and there would be NO surpluses to offset the budget deficit.
BUT, I could be wrong.
[Edit/Afternote (6 Aug) : Then Minister for Transport announced fare decrease of 1.9% at the end of the year, and the opening of 12 stations on the Downtown Line 2 on Dec 27.
And it is seemingly more certain that Sept 2015 is not going to be elections.
Still thinks it will be May 2016.]