Korea will celebrate its annual Lunar New Year holiday from Feb. 13-15. I have some recommendations.
This year the holiday is Sat., Sun, and Monday (a legal holiday). For your Korean colleagues in Korea, you can wish them Happy Lunar New Year by phone or email on Thursday Feb. 11 (which is Friday in Korea).
For Koreans working in the U.S. or globally, you can wish then Happy Lunar New Years on Friday Feb. 12 (pm) or on Monday Feb. 15.
Here is the formal greeting, Sae hae bok mani ba deu say yo. Or, just say Happy Lunar New Year.
I suggest you also share with your non-Korean team the significance of the holiday. Here is some info to share with the team:
2010 Korean Lunar New Year
The 2010 Lunar New Year celebration (Seol) is Feb. 13-15. This is the year of the Tiger.
Along with Chusok (the fall harvest festival), Lunar New Year is the most important of traditional Korean holidays.
Throughout its history, the tiger may be Korea's most beloved animal. The country was once dubbed the "nation of tigers'' as it has mountainous areas that provided them with a good habitat. (Those that hunted tigers were also seen as "the bravest of the brave." ) The animal has been a symbol of strength and dignity. 2010, the Year of the Tiger will be welcomed as a year for fortune and vigor in business.
In Korea, Seol includes gift-giving and family activities that show respect to elders and ancestors. Most Korean businesses are closed for the holiday.
Hope this is helpful, Sae hae bok mani ba deu say yo.