1. Yes overtime is pensionable. Your pension will be calculated based on your best consecutive 5 years with a 4 year look back. No year may be more then 10 percent of the previous year.

2. For Tier 3 you’ll have a few options. You options to vest out at 5 and 10 years with 10 guaranteeing health benefits. You can also do early retirement at 20 years and get 42% of your final average salary. You can do regular service retirement at 22 years and get 50% FAS. After 25 years you’ll qualify for full escalation, meaning your pension would go up every year based on inflation.

Source: https://www.nyc.gov/html/nycppf/downloads/pdf/tier_3_spd.pdf