Have to be there five years to get anything. Then you get (1.5x number of years worked)% of your income as pension. BUT you can't collect before 65 without taking major penalties unless you've put in 35 years. There are penalties on penalties on penalties.
I know someone who put in 35 years. Didn't retire until after 65. He was shocked at how many penalties he was still charged and how big of a chunk it took from his pension.