Do you tell someone when you are going on a date with someone new?

Be honest - how often do you tell someone where you are going and when you are expected back. Almost never, I bet. And that is fine 99% of the time. 

It's the 0.01% of the time when something happens - people need to know where you are. This is a system so the people you trust can come and find you or alert emergency services to find you if you are in real trouble. 

If you get back it time hit "I'm safe", no sms will be sent.

If you don't get back in time:

Look after the people who love you by looking after yourself.