This issue actually stems from an issue with UTC time not coming through from Salesforce properly. My workaround was to create a new column that adjusts for the time zone properly, and then assemble the date & correct time together into a new column.
but when published, that column is completely blank on web reports. CreatedDate_day is formatted from the imported "CreatedDate" from Salesforce, and CreatedTime is a date/time/timezone column that I'm just taking the "time" from.
Any idea how to get the column to not be blank on the web?