if you are applying for citizenship, the question on the n400 form

Part 3. Information About You

C. Date you became a permanent resident (mm/dd/yyyy)

if you are having trouble answering this question. lets see if i can help you. this is how you get the answer to this question.

1. get your green card on had.

2. once you have it on hand, look at your green card, look for the date where it says: Resident Since:
23-p8668-green-card-example.jpg

in my example above, the date is 08/21/07

IMPORTANT!!!! be sure to use the format they are asking you to use. for example, on the green card the date says 08/21/07 , but you should write it on the form as: 08/21/2007