When combining data from four data sources, you notice that timestamp data about transactions are represented differently in each of the data sources. The timestamp for one transaction is presented in each source respectively as follows: "Fri, $21$ Jan $202200$:$02$:$09$ UTC," "Friday, January $21,202207$:$02$:$09$ AM$,""1642748529,""44582\mathrm{.}2931597222."$ The first source uses UTC, the second uses the local time zone, the third uses the Epoch timestamp, and the fourth uses the Excel timestamp. All represent that same exact time. How would you determine which timestamp to output in your transformation?