You can deduct charitable contributions made in 2016 on your 2016 tax return. You can not deduct contributions made in 2017 on your 2016 tax return.
And they may or may not provide a tax benefit. That is an itemized deduction. Itemized deductions provide no tax benefit until all of them added together are more than your standard deduction.
2016 Standard Deduction
Taxpayer under 65, not claimed as a dependent
$6,300 for Single
$12,600 for Married Filing Jointly, or Qualifying Widow(er) with dependent child
$9,300 for Head of Household
$6,300 for Married Filing Separately
For over 65 or blind, add $1,250 for each instance or add
$1,550 each instance if single and not a surviving spouse.
