In an age where the importance of data needs no emphasis, it is no surprise that asset managers have begun to accelerate their collection of information from multiple sources in varying amounts. These sources can range from a file provided by a broker or fund admin to a market data provider. Although it rarely occurs, there are times when historical data can be incorrectly provided or maintained by the data source. In a unitemporal scenario, a user can rectify the historical record of data for the timeframe in which inaccurate data was provided or maintained. However, in doing so, the user erases the previous record that was once thought of as correct.