If you're running employee timecards and get a message that "No entries were found matching your selection request" then there are a couple of things to check before concluding that the timecard entries are missing. First, double-check the date range and worker selection. You may be trying to run a timecard for 'Yesterday' for someone who didn't work yesterday.
Next, make sure someone hasn't made changes to the default report settings in the Report Writer. Click Report Writer in the Configure menu. Click the Selection & Sort button for the timecard report you're trying to run and make sure the Who and Entries popup menus haven't been changed to only include a limited selection of people or activities. Someone may have been experimenting with report settings without making a copy of the report first.