Sick Day is an episode of the ALVINNN!!! and The Chipmunks series.
Alvin and Kevin pretend to be sick to miss school and sneak off to the Dagarack Convention.
Alvin's loud coughing gets the attention of his brothers. While Theodore retrieves Dave, Simon questions whether or not Alvin's actually sick given the day is the day of the Dagarack Convention. Dave doesn't initially believe him either, though Alvin seemed feverish and he's sneezing with watery eyes. Dave calls the doctor, who's dealing with multiple similar cases, and allows for Alvin to stay home as he goes to a meeting. Once Alvin's sure Dave is gone, he calls Kevin to meet for the convention. Meanwhile, Dave reschedules his meeting after learning the Dagarack Convention is next door. Dave sees who be believes is Alvin at the convention so he calls Simon to confirm his supposedly sick brother hasn't been seen. Taking Simon's advice, Dave video chats Alvin in order to check up on him, but Alvin and Kevin fool Dave with a fake background. An announcer reveals Alvin S. to be the winner of a signed Staff of Wonderment and he rushes to pick it up while avoiding Dave, who he tracks via a tracking app on his phone. Being close to being caught, Alvin enlists the Imperial Guards to jail Dave in the Misery Mines. Dave calls Simon again, who rushes home. Alvin and Kevin hide from Dave once he's released and then too rush to get back home, while Dave pursues. Simon beats them all, ready to confront Alvin; hearing noises from Alvin's bed though leads him to apologize for not trusting his brother. Dave finds himself stuck behind a flock of birds so he video chats Alvin once more, this time learning he's not actually in bed but instead on the bus. Dave calls Simon, who believes he's talking to Alvin, and learns it's really Theodore, given candy to be quiet, in Alvin's bed. Simon is not a happy camper and confirms to Dave that Alvin was lying the whole time. Dave texts Alvin that he is grounded for three weeks with additional duties before Alvin accidentally breaks the staff he won.
- "Faster Than the Sun" 
- This episode is a callback to the season two episode Brothers of Dagarack.