Marko Nikacevic enhanced timestamp handling in the xupefei/spark repository by implementing ANSI-compliant functions for robust SQL and Python interoperability. He introduced the try_make_timestamp family, which throws on invalid inputs, replacing previous non-throwing variants and aligning the API with ANSI-by-default standards. Using Scala and Python, Marko improved error diagnostics and updated error messaging to guide users toward safer parsing methods. In a subsequent update, he addressed a bug in timestamp parsing by changing parameter types from Decimal to Double, resulting in clearer error reporting and more stable backend behavior. His work demonstrated depth in data engineering and error handling.