Using the to_timestamp() function, I am able to convert timestamps from a variety of text representations of date time.
I can see in the function call here that a single timestamp pattern is used for the entire column, which can produce null outputs for the rows whose text does not match the given pattern. Since the to_timestamp() function takes the timestamp pattern to be used as its first argument, I will need to make another function call with the appropriate pattern in order to convert these differently formatted text strings to timestamps as expected.
For more information on writing these patterns, please follow the [definition of the to_timestamp() function](https://community.denodo.com/docs/html/browse/8.0/en/vdp/vql/appendix/syntax_of_condition_functions/date_processing_functions#to-timestamp), and the [Date and Time Pattern Strings ](https://community.denodo.com/docs/html/browse/8.0/en/vdp/vql/appendix/date_and_time_pattern_strings/date_and_time_pattern_strings#date-and-time-pattern-strings)section of the VDP VQL Guide.
Additionally, I would open the relevant View in the Virtual DataPort Administration Tool, and click on the Summary panel to verify columns used for my function inputs are of Field Type ‘text’ as expected.
Hope this helps!