Handling confusing date convention formats

One of the most common data integrity issues encountered when dealing with date time values involves the inconsistent positioning of the month and date values in data entries and transactions. In some countries, mm/dd/yyyy is used for the date format. In other countries, dd/mm/yyyy is used. Of course, the number of days (that is, 01 to 31) exceeds the number of months (that is, 01 to 12). However, what if the record stored in the sheet or database is 03/06/1990? If the assumed format is mm/dd/yyyy, then 03/06/1990 will be interpreted as March 6, 1990. On the other hand, if the assumed format is dd/mm/yyyy, then the same date will be interpreted as June 3, 1990 instead.

Now, we have a data integrity issue when a single column involves both formats. There are a variety of reasons this could happen and one of the possible causes is if records from multiple data sources were merged into a single sheet or table without taking into account the...