Real English Fifty-One: by/until

Today is the last day of 2013.
Tonight, before the clock strikes 12, I will take some time to reflect on this year.
Needless to say, it has been a big year for me...

And I decided my New Year's resolution for 2014.
I have a few.

My first resolution is to continue to write 52 Real English segments in the year.
There are 52 weeks in a year, so basically this means that my aim is two write one Real English segment a week. 

My second resolution is to read one book a month.
So that means that I hope to read 12 books in the year.

My third resolution is to do 80 pull-ups in 30 minutes by the end of the year.
Not 80 pull-ups in a row! 80 pull-ups within 30 minutes!  So that means doing 10 pull-ups, then taking a break, then doing 10 more pull-ups is OK!

What is your New Year's resolution?

And tonight is New Year's eve.
I want to stay up until midnight and watch the apple drop, but maybe I can't.

Do you know how to use both "by" and "until" correctly?
Most learners of the English language don't know the difference between "by" and "until" and find it difficult to them.
Many people say, "It is confusing!" or "I am confused!"
In 2014, let's make sure we get it right!