The 'Dancing With the Stars' pro also tells ET that their nuptials will take place sometime next year.
ET caught up with the Dancing With the Stars pro at the Hollywood premiere of former dance partner Victoria Arlen's book and short film, Locked In, on Thursday, where he gave us an update on his upcoming nuptials.
Chmerkovskiy explained that he and Johnson, who got engaged in June, have not set a final date just yet, but they have selected the month they plan to say "I do."
"We have kind of the time, the month," Chmerkovskiy told ET's Deidre Behar. "We've narrowed down the month, which is sometime next year."
"It's awesome," he added, of what life has been like since becoming engaged. "It's like Groundhog Day of awesome every day. I wake up, I'm like, 'Wow, that's great. I get to keep that forever!'"
It was a true DWTS red carpet reunion on Thursday, as plenty of pros and former contestants, like Sharna Burgess, Peta Murgatroyd and Drew Scott, came to support Arlen on her big night. The former paralympian swimmer joined Chmerkovskiy during our interview, where the two joked about her potentially officiating his wedding.
"No, no! " exclaimed Arlen, when we brought up the idea to her. "I would straight-up cry. I'm such a sap at weddings."
"First of all, she's more than worthy, but as you can tell, she's not very excited about it," Chmerkovskiy joked. "So, I wouldn't put her in that spot."
Arlen told us, however, that she's currently single at the moment, but when she does find the one, she would happily have Chmerkovskiy officiate. The two have remained tight pals since competing on season 25 of DWTS together. So close, in fact, that Arlen asked him to write the foreword in her new book.
"I'm so proud of her," Chmerkovskiy raved. "She means a lot, and two and a half pages, which was the limit I was given, was not enough, obviously."
Back in July, ET also caught up with Chmerkovskiy at the grand opening of fellow DWTS pro Gleb Savchenko's new dance studio, Pro Dance LA. The dancer attended the event with Johnson, and they couldn't seem to help themselves from gushing over each other (and how the proposal went down!) during our interview.