I would love to have the correct answer on this question for those who have had experience on the issue.

What is the correct number of months an unconditional resident is allowed to stay outside the U.S and return with no hassles. In the past i have gotten dissenting views on this question. Some say 6months, others say 1 year. I know the USICS website states as follows on international travel:

International Travel
A Permanent Resident of the United States can travel freely outside of the US. A passport from the country of citizenship is normally all that is needed. To reenter the US a Permanent Resident normally needs to present the green card (Permanent Resident Card, Form I-551) for readmission. A reentry permit is needed for reentry for trips greater than one year but less than two years in duration.

Your thoughts on this issue is greatly appreciated.