"We loved our road trip yesterday @dylandreyernbc" Hoda wrote.
Dylan also shared a few nice photos (and a video!) from the day on Instagram.
"What better way to meet Oliver than to serenade him," she wrote. "Fun Sunday with friends!"
In the pictures, 2-year-old Haley plays with a toy trumpet and 3-year-old Calvin plays with some drumsticks while Ollie looks on from his spot on Hoda's lap.
The video gives even more insight into the musical get-together, where Calvin and Haley played tunes on the piano and drums.
It marked the latest hangout session for pals Haley and Calvin.
The two little friends have previously spent time having fun at the beach, going to see "Sesame Street Live" together and making sure they sat next to one another at Calvin's awesome third birthday party.
It was also nice to see Dylan all smiles during the visit on Sunday considering she was coming off a rough week in which she had her hands full with Calvin and Oliver.
“Not gonna lie. This week is kind of a rock bottom week,'' she admitted during a phone call to TODAY on Friday. "Calvin is acting out. He’s screaming in his bedroom right now. They wouldn’t allow him in school ‘cause he wouldn’t stop kicking and screaming. But I think it’s because he’s (Ollie's) been more needy this week," she said.
"I don’t know if he’s gassy or what, but he’s up all night. He’s crying all the time. He’s needed a lot of attention, so it’s just spiraling out of control right now,” she added.
Luckily, Dylan had the two-step antidote to help her make it through the rough patch. First, a visit from her fellow 3rd hour of TODAY host Sheinelle Jones to take Oliver off her hands for a little bit.
Then the sweet meeting with the always fun Hoda and Haley Joy on Sunday. That's a great way to start the week!