I have a Google spreadsheet that I use to track the status of configuration information requested for an app, from a client. E.g. Text to go on a button. 
I have a column with 'Status' at the top and cells with 'List from Range' Data Validation in the rows beneath. The range used has 'With client', 'With Me', 'Completed'. I also have a column to the right which I use to manually add the date the last time the status changed. What I would like is for the date to be automatically changed to today's date when I change the status. I believe it can be done with a script but I have never used one before.