I love this one...it never goes away. I was raised in the UK and have lived in the US for the last 14 years, and it still creates confusion when communicating across the pond.

My old UK dictionary has both "every two" or "twice per" listed, and it depends on whether the term was being used as an adjective or an adverb.

Many people refer to the commonly used biweekly [adj] publications as proof that its "every two," yet my US company gives me a bimonthly [adj] paycheck twice per month (their term not mine).

I find most confusion occurs around biweekly [adv] meetings. UK tends to see it as "twice per" and US as "every two." Even though most know what the other is saying, there is always need to clarify the intent. Fortnightly doesn't work outside of the UK so that's not an option either.

To further make a point on how confusing it is (in the UK) a biweekly meet is every two weeks, because a "meet" is a noun typically used in Fox Hunting.

I have given up listening to who is right and wrong, and at the end of the day who really cares? Its a pointless discussion as you will never convince the other person they are wrong. You might gather all the data to prove you are right, yet the other person will find an equal amount of data to prove you wrong. Its just not worth it.

My advice is to explicitly state your intent, otherwise many hours will get wasted and worse you may come off looking like a complete idiot if you try to push an argument you can't win in the other persons mind.

Case in point, if you are reading this post, ask yourself why you are here and how many other posts did you read before this one? If you are not convinced its a bad idea to push for one or the other...continue searching ;-)