To remove financial periods, go to Step 1: Update Data in the setup for your company. Under the 'Financials' section, there is a link called 'remove periods'. Here, you can remove the incomplete or future periods from your company.
You can also remove periods to see YTD results to a specific period. For example, if you remove July to December 2016, your YTD results should display as expected (to June).
At any time in the future you can then update and re-import results for these periods, when these periods are ready for analysis.