You can make contributions any time...but when you make them in the year determines what tax year they are reported in. You can claim the deductions in a later tax year if you choose, but the only way you can get away with claiming contributions made in the first 60 days of a calendar year on that year's tax return is if the contributions made in the first 60 days of the following calendar year happen to be for the same amount...in which case the numbers match, however at some point along the way you will miss out on a deduction.
