Thanks for reaching out to Jotform Support. If you're referring to the Approval Activity History in the PDF output, let me walk you through how to add the time:
Open the PDF Editor.
Click on the Gear icon on the Approval Activity History element.
Scroll down to the Form dropdown in the Date Format section.
Select the Date format that includes the time.
If that’s not exactly what you’re looking for, can you explain a bit more so I can help you better?