SAN DIEGO (FOX 5/KUSI) -- It’s been a holiday tradition at this place for almost three decades. And during that time, millions of people have smiled as they drive through Mission Valley. Almost everyone has their own holiday tradition. But there’s only one hotel that brings the "joy" year after year -- it’s the Hilton Mission Valley. How to prepare for holiday travel at San Diego International Airport "We’ve been spreading the joy here along the 8 for the past 30 years. It's been a tradition at this hotel, from Thanksgiving up until right after the new year to display 'joy' in the windows," said Dan Evans, Hilton Hotels. For all the people who’ve seen it, many have wondered how they do it. Is this a hotel that puts "joy" ahead of profits. Do they leave these rooms empty in order to light up the night with "joy"? Marine Fighter Attack Squadron returns home from combat deployment in time for holidays Just like the holidays themselves, there’s a little magic involved in bringing joy to the world. These rooms are carefully blocked out and set aside especially for this event. Hilton Mission Valley brings 'joy' to drivers along I-8 (Photo: Hilton San Diego Mission Valley) Hilton Mission Valley brings 'joy' to drivers along I-8 (FOX 5/KUSI) "It takes about 78 rooms that we block if possible, that way we can display it. We simply move the lamp in the window and open up the shades for that," said Evans. In the event that the hotel is completely booked -- this can get a little tricky. In order to spread the joy, they ask travelers to play along. Where to find holiday light displays in San Diego "So if we have people we do our best to not check them into these rooms. However, if our occupancy is high enough we ask the guest when they check in if they are okay with participating, most people are. We just simply ask that if they want the lights off they close their blinds," Evans explained. The blackout curtains are so dark that the people inside the rooms can’t see the light. The San Diego hotel is bringing the joy this holiday week with Christmas on Dec. 25 and Hanukkah starting the same day, followed by Kwanzaa, which begins on Dec. 26.