Zooey Deschanel and Joseph Gordon-Levitt, the charming duo from the romantic comedy (500) Days of Summer, teamed up once again. This time to roll out an adorable duet, covering Nancy Wilson's classic song What Are You Doing New Year's Eve, for Zooey's YouTube channel HelloGiggles.

The low-production video has made it to the top of YouTube trends and has garnered over a million views within a day of uploading.

Zooey wrote of her friendship with Gordon-Levitt in a blog post accompanying the video: We bonded over a mutual appreciation for Harry Nilsson and Nina Simone, and I have been lucky enough to call him one of my dearest friends ever since, she wrote.

When we did 500 Days of Summer eight years later, we spent every lunch hour dancing to Marvin Gaye in the hair and makeup trailer. We had loads of fun. I hope to do a thousand more movies with him, because he's simply the best, she gushed.