Johnstone said her friend Jo McLean was the founder of the kaupapa, which started in Gisborne in November.
Inspired, she then decided to bring the kaupapa to Rotorua. The first gathering was last night at Brew Bar on Eat Streat, with more events being organised for the summer.
Johnstone said two of her sons had been diagnosed with ADHD, while some other relatives had faced mental health challenges. She also studied psychology and has worked in the disability community, which she was passionate about.
“I just see that there’s a huge need out there for awareness and for understanding and for people to be uplifted and empowered.
“It’s just about having fun and feeling nice and good about yourself and ... raising awareness at the same time.”
Being a mother, Johnstone said she would normally “chuck the same things on [and] tie your hair up in a mum bun”.
But after putting on a dress that had been in her wardrobe for four years and some different shoes, she says: “I feel really nice even though it’s raining.
“It’s something easy that people can do.”
People could give a koha if they wished, which would go to a mental health charity or to people who were affected by mental health challenges.
Founder of Frocks on Friday Jo McLean said it was a way to inspire people to “just be brave and wear the dresses and not save things for special occasions”.
“Because every day that we’re here is a special occasion.”
McLean said it had “blown me away” how fast the kaupapa had grown, with the Facebook group having about 1400 members.
Members had started creating their own events such as a sunrise ocean dip and going for a 6am run “on our big hill in Gisborne” in dresses.
“Everyone is encouraged to make a donation if they can, even if it’s just a $1 each Friday ... when you have a large number of people doing a small thing over and over again, then it can have a big impact.”
Donations will go towards Rotorua whānau who needed mental health support, she said.