It will extend your citizenship wait period by 8 months. As long as you didnot violate the residency rules which looks like you did not it is theaccumulated time in US is what counts against your waiting period not thetotal number of yearsmonthsdays. Since you were absent for 8 months totalyour application will need to wait until the 5 years and 8 months from date ofyour green card issuance.EditCorrection I misread the 8 months absence statement and was under theimpression that total of these 3 absent periods were 8 months. But I see nowit is not the case.If you are currently in the US I think you did not have the problem ofexplaining USCIS why you were out of the country for 8 months as it would havemore than likely be an issue. May be you had an advanced parole or reentrypermit. But correcting my previous answer which I am not touching above thetotal amount of time you need to add to that 5 years long waiting period isnot only 8 months but the total amount of time you spent abroad in all 3trips of yours.