New Year in February???

About a month ago we celebrated the beginning of a New Year (1st January), but in other countries like Korea and China they celebrate their New Year in February... The question is WHY?

 
Korea - "Eumnyok Seolnal" (Lunar New Year)
is celebrated on February 3 (tomorrow). Korean New Year generally falls on the day of the second new moon after winter solstice. The THREE-DAY HOLIDAY is used to visit their parents and other relatives where they preform the ancestral ritual known as "charye." 

                    

China - February 3rd (tomorrow) is the "Xīnnián (New Year). Is the longest

and most important festivity in the Chinese Lunisolar Calendar, and 2011 is
the year of the "Tù" (rabbit).