Depending on what province you live in, you may see two columns to enter your tuition amounts and FT/PT months. One column will have a date range and the other that says “Total For 2017” on top. The first column is for the provincial tax credit. Several provinces have changed or eliminated their tuition credits, and so you can only claim tuition for the part of the year when the credit was still available.
The “Total For 2017” is for the federal tax credit, and there you can claim any eligible tuition that you paid during any part of the year. Anything on your T2202A for 2017 would be considered eligible.