Tivoter

Hello, I am new to Labview and I am trying to used the "Basic Trigger Level Detection.vi" to detect threshold (DC) changes. My problem is that I want to record the time it takes from the zero time (when I start the vi) to the time (in seconds) to the moment when the threshold is passed and send the data to excel. I cannot seem to understand how to take the starting time and the threshold passing time and log it! how can I do this? Please guide me! Thank you