How much property tax can be paid in advance?

In my writing about timing one's deductions to itemize in alternate years, I've suggested pulling in the tax payments from the next calendar year, e.g. the '15 Q1 and Q2 payment into 2014. As a cash basis normal taxpayer, would this be an issue come audit time? I'm assuming a town fiscal year that runs July - June, so by Dec '14 I have my bill for 1H

I'd just like to verify this isn't opening up some unforeseen issue.