Is an overstay cumulative? Can a person enter and exit and stay more than 180 days?

[IVPA]

Is it an overstay if over the last year I spend more than 180 days (but less than 365)in U.S soil, but I never stayed for more than 50 consecutive days? From August 2016 to june 2017 I spent most of my days on the U.S. I never had a job, or a house (stayed with friends). I had my b1/b2 visa, and since my family lives in a border town in Mexico I kept crossing for a weekend every moth or month and a half. Again, I never stayed for more than 180 consecutive days in the U.S. Plus, over that year I actually got two I-94 pemits for six months each. I never had any problem crossing the border, or asking for the I-94 permits. I even got a traffic fine once and didn't get into trouble. The last time I crossed the border was for just 2 days, just 2 months ago, and then I exited the U.S by plane. Now I have an interview in the consulate, for a working visa, (I already have an approved I-129, again, no trouble) If I haven't gotten into trouble this far, (and I don't really know if I have done something wrong), is it possible that during the interview something goes wrong and I get my working visa denied, or even banned?

Also, a kind of different question. I am currently in Italy, can I fly from here into the u.s, then cross the border immedaitly to Mexico, to attend my consulate interview using my b1/b2? Will that affect my interview? I already filed the DS160 and entered the estimated dates of my last entries in to the U.S, so, can I enter again before the interview?

[inadmissible]

For the unlawful presence ban, unlawful presence is not measured cumulatively

For the illegal re-entry ban, unlawful presence is measured cumulatively

Be prepared to furnish records or other evidence you were inspected on each entry

[newacct]

Is it an overstay if over the last year I spend more than 180 days (but less than 365)in U.S soil, but I never stayed for more than 50 consecutive days? From August 2016 to june 2017 I spent most of my days on the U.S. I never had a job, or a house (stayed with friends). I had my b1/b2 visa, and since my family lives in a border town in Mexico I kept crossing for a weekend every moth or month and a half. Again, I never stayed for more than 180 consecutive days in the U.S. Plus, over that year I actually got two I-94 pemits for six months each. I never had any problem crossing the border, or asking for the I-94 permits. I even got a traffic fine once and didn't get into trouble. The last time I crossed the border was for just 2 days, just 2 months ago, and then I exited the U.S by plane. Now I have an interview in the consulate, for a working visa, (I already have an approved I-129, again, no trouble) If I haven't gotten into trouble this far, (and I don't really know if I have done something wrong), is it possible that during the interview something goes wrong and I get my working visa denied, or even banned?

Also, a kind of different question. I am currently in Italy, can I fly from here into the u.s, then cross the border immedaitly to Mexico, to attend my consulate interview using my b1/b2? Will that affect my interview? I already filed the DS160 and entered the estimated dates of my last entries in to the U.S, so, can I enter again before the interview?

There is no rule on how many days in the year you can spend in the US or how long before you can come back for another stay. Each time you seek entry to the US, the officer will decide whether to admit you and for how long, and it doesn't necessarily have anything to do with how long you have spent in the US on past trips. As long as you have not stayed past the date they admitted you for each time, you have not overstayed.