If the time on the PC and the connected instrument are different, which time is recorded, SMARTDAC+ GA10's or connected instruments'?

In the data acquisition parameters, under “Data time," you can select "Use PC time" or "Use instrument time."
See section 12.2, question 12: “What is the difference between setting the Data time to PC time and setting the Data time to Device time?" in user's manual IM 04L65B01-01EN.