Significance vs Importance - What's the difference?

To check if something is significant we can say "how long will it matter?" while to check if something is important we only have to ask "how much does it matter?"

Bonus: When we want to check "how fast will it matter?" we can call it urgency.

We want to do things that are significant for us (relationship with a sister is usually more significant then this work task at hand), important (they are needed in present!) and urgent (deadline is coming!).