"It's A GREAT MOMENT when someone has character to step up and do the right thing at the right time". - Pam Knox 

What this is saying is that steping up and doing something positive is the correct thing to do at the right moment. For example if you see someone getting bully even though its not a great moment for the one that's getting bully. That's a perfect moment to step in for somebody and defend them because you are doing the right thing for steping up for someone who is getting hurt. You should always step up in what you believe in at the right moment and time.