1 Button that timestamps the next empty time field?
I'm not really sure if I am asking this correctly. I know very little about javascript. I created a pdf form that is used by officers to track daily tasks in relation to a certain project. There are several lines- each line a different task or action.
Example:

Each row has a start and stop time.
I know how to create a button that will put a timestamp in a field. There are 24 rows in this sheet, so to do it the way I know how - would be 48 buttons (one button per row for start, one button per row for stop). That's a lot of buttons and a lot of real estate on my form, even if the buttons are tiny.
Is there a way to have a button that timestamps the next empty time field? I am not sure that makes sense, but have like 1 button that when clicked - puts the current time in the next "not null" time field?
Thank you.
