Jeff's correction is excellent, and I can't improve on it. Instead, I'm going to write a "natural casual English version" of my own. Hopefully it will help your study a little.

Tomorrow it's a holiday in Korea.

Tomorrow, it will be "Chusok", a Korean holiday. It's kind of like Thanksgiving in America. Traditionally, it goes for three days - but this year we get an extra two. So we get a whole five days off!

I really love these kinds of holidays!

One thing that is not clear from your English. With your last line "I'm so happy this special holidays", do you mean that you enjoy traditional Korean holidays (because they are Korean cultural traditions); or do you mean that you like (any) holiday (that isn't a regular one ie. weekends); or do you mean you like holidays which get extended (ie. three days gets extended to five days)?

Tomorrow is the start of a holidays in Korea, called Chusok (Mid Autumn Festival). Chusok It is something like Thanksgiving in the US, a day of family gathering. Day of Korea. 

We take a rest 3 Traditionally, we have three days traditional but this year, we have two more/extra days, a total of a five holiday period.  2 more holidays! so We rest 5 days!!!

I'm so happy on this special holidays.