You can't save up deductions for a future year when you can use the itemized instead of the standard deduction. The only way to claim the tax deduction in 2018 is to actually pay the tax bill on or after January 1, 2018. If that means you have to eat a late payment penalty from the city or county, you will have to decide whether it is worth it.
Note that if you try and do something clever like paying in December with a post-dated check, and the city successfully deposits the check in 2017, then it's a 2017 payment even though the check is dated 2018.
