Your friend might not be lying. Your friend might have done lots of research before giving the GMAT at the right time . I think I will wait for other peoples thoughts. Because this is the first time I heard like this, however there is a truth in that. By the way thanks for creating this thread. It will help me a lot in future as it might help you too. I don't wanna compete against best . All I want is my GMAT score to be BEST.

Good question - I've heard this rumor before, and have a general rule for debunking these. Ask the question:

Does it make sense for business schools to support this policy?

Much like the rumor that "the first 10 questions are worth significantly more than the rest" is false because, well, why would the GMAT want to reward that kind of "gamesmanship", this one also doesn't make sense.

The GMAT's primary task is to report to business schools which candidates are the most capable of success in b-school and beyond. To effectively levy a "July penalty" to unknowing test-takers wouldn't serve that purpose at all. Business schools want a score that reflects your competitiveness among candidates applying to school that year, not merely against those who took the test that day. Because of that, the GMAT has a responsibility to calculate your percentile and score using the scores of others over time.

The people behind the GMAT take the validity of its statistics incredibly seriously, and issue ongoing public reports (available at www.mba.com) to demonstrate it. I don't have specific information regarding how the percentiles are calculated, but I have complete trust in the people behind the GMAT's scoring system - I've met a few of them personally - that they wouldn't allow the type of statistical anomaly cited in that rumor to be a contributing factor in admissions decisions.