There is a date issue in the report browser (list view) where it is not defaulting to 0:00 and shows the current time instead in 7.1. The expectation of the user is that the time would be defaulted to 0:00 for 24 hours format and 12:00 AM for 12 hours format based on the locale. It used to work in similar manner in 6.1 so user expects to have the functionality behave in this manner in 7.1 as well.
STEPS TO REPRODUCE
1) Create a ListView report with a DateTime property . Also, let the Content tab have DateTime property in the Filter Conditions.
2) Create a Shortcut under Monitor Assignments category and include the created List View report.
3) Launch the portal and click on the shortcut.
4) In the new window that opens the report in new window click on the Filter for Date column. Then click on the Calendar icon and it can be seen that default time is picked up as the current time.
I have tested the scenario in both the environments., i.e., in 6.2 SP2 and 7.1.6. In both the scenarios, the default time for the calendar is the current time. Can you please specify the exact version in 6.x where you find default time as 12:00 AM ?