For the contribution to count for this year, the funds must be received by your superannuation fund by midnight on 30 June, which just happens to fall on a Friday this year. But employers are required to pay the compulsory superannuation quarterly, not monthly. This means they have until the middle of July to make the contribution, which could take some of their employees over the limit for the next financial year, while not allowing them to use the full cap this year.
Savvy employers will work with their staff to ensure the contributions are made before 30 June, and so give themselves a tax deduction in the current financial year. Savvy employees will take note of this and work with their employers to make it happen.