How long does the temper tantrum stage last and any advice to help 19 month old and parents through it?

I know kids and even adults have some form of temper tantrums throughout the entirety of life. But, our sweet little angel over the last couple weeks has been going through something. Basically everything that is even slightly against what she wants leads to a full blown temper tantrum. It’s tough to know when to console her and when to let her ride it out. Any advise would be great. via /r/Parenting https://ift.tt/2ya28wO