what year did the big bang start

Question: what year did the big bang start
- Keywords:
  big bang
Asked by art to Pip, Kuntal, Kate, Ajay on 8 Nov 2016.
- Kate Elliott answered on 8 Nov 2016:
  
  It was about 13-14 billion years ago. It wasn’t in a year because our planet is only about 4.5billion years old, and humans have been around even less time, so years hadn’t been invented when the big bang start!

Question: what year did the big bang start