Hi @Rafael_Gramza, please surround your code with back ticks to improve readability - see here.
It seems that you are using Builder with a code component, as you have the Begin and End experiment tabs, if not please let me know. If using Builder, this will create a variable called globalClock, which tracks the time from when the experiment started. So, in the “End Experiment” tab, you can add the following to get the final time in your data file:
thisExp.addData("globalClockTime", globalClock.getTime())
thisExp.nextEntry()