Before learning about Tết in Viet class, my knowledge on the subject was really limited. When Tết came around, all I really noticed was that red envelopes containing money, called li xi, were passed out to the younger kids and teenagers, special food specific to the holiday would be bought and made, and offerings were placed on the altar. I just didn't know the reason behind everything.
I learned that Tết usually falls between the last week of January and mid-February, depending on the lunar calendar, which marks the arrival of spring. This year, Tết is on February 3rd and it's the Year of the Cat. Unlike the New Years we celebrate here in the U.S., Tết lasts for three days and there's more to it than simply making a New Year's resolution.
The week before New Year's Eve is called "Tat Nien," which means "to extinguish the year." Right now at home, my mom is making food to offer to the altar to signify the end of the year (which I told her I had just read about that). In preparation for Tết, cleaning has to be done beforehand or else it's believed that good fortune will be "swept away." After the three days, the floors may be swept but the dirt has to be kept in the corner for two days before being thrown out! I doubt my mom has actually done that though.

I also learned where li xi originated from. There's a story where an evil spirit went around petting kids' heads as they were sleeping, resulting in the children waking up in shock and screaming in fear. One day, a couple genies realized what the evil spirit was doing and they left eight dollars wrapped in red paper next to a child's pillow. When the evil spirit came by, the red paper lit up and scared it away. From then on, children are given li xi's to ward off the evil spirits. All this time I never wondered why li xi's were always given on Tết either but it's interesting to know the story behind it.

Another thing that I saw my parents do, but never understood myself, was when they would buy paper money and aluminum gold bars to burn and cook food to set out in front of the altar. I learned that they burned these "money" and "gold bars" so that our ancestors can take them back with them to Heaven. I found out that my parents cook and offer food as an invitation to our ancestors to join us to eat for Tết.
Speaking of which, I'm going home this weekend and can't wait to spend time with my family and eat some Vietnamese food for Tết! Maybe I'll even get a li xi.