Here's a short story:

Yesterday, Emily and Evelyn went to the zoo with their mom. They left the house right after breakfast so that they would be there when the zoo opened. Once inside, they raced to see the monkeys swinging around their cages. There were even two baby monkeys! The girls also enjoyed feeding birds in the walk-in bird cage. The birds were very interested in picking seeds from the popsicle stick that Emily held out to them. Next, it was time to stop for ice cream. Each girl chose a small cup of soft ice cream. Emily chose a swirl of chocolate and vanilla and Evelyn had chocolate. Ice cream at the zoo was the perfect treat on a hot summer day. The best part of the girls' visit was the giraffe area. They walked past rhinos and tortoises to get to the giraffe area which was on a raised deck. The giraffes stretched their necks up to the deck to eat leaves and hay that were placed there for them. Emily and Evelyn bought special crackers to feed to the giraffes. Emily liked that she could pet the giraffes when they reached out to grab the crackers with their long tongues. Evelyn liked to watch the giraffes, but did not want to feed one herself. After feeding the giraffes, the girls left the zoo, hot and tired and ready to return soon! (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Here are a few examples of questions and answers:

Question: Who went to the zoo?
Guess: Emily, Evelyn, and their mom

Now answer the following question in the same format.

Question: When did they go?

Yesterday