Facebook Page Insights: "timestamp" vs. "date" Columns Explained

When I look at my fetch results from Facebook Insights, I see two columns called "date" and "timerange", which show different dates for the same data row? Why are they different, and which one is correct?

"Timestamp"

This is the date of data capture, as recorded by Facebook's API. Facebook always captures data 24 hours in arrears, meaning that data with the timestamp "02.MM.YYYY" actually relates to activity that took place on 01.MM.YYYY.

"Date"

This field is generated internally by Datatap, and relates to the date of occurrence, so data with the timestamp "02.MM.YYYY" actually relates to activity that took place on 02.MM.YYYY.