Other years Mount retailers had run raffles to fundraise for shops caught open and fined, she said.
But this year there was no need to be furtive and retailers could make the most of holiday shoppers in a "spendy mood".
"That's what gets us through winter."
Mount Mainstreet manager Ingrid Fleming said the organisation was marking the occasion with Easter-themed events including an egg hunt and visits from the Easter Bunny.
Retailers were "very pleased to be able to legally open if they want to", she said.
Less pleased was Tali Williams of First Union, who said many workers had been in touch unsure about whether they could refuse to work and what they should be paid.
"There is a lot of confusion about what their rights are because it's the first year."
She said some rostered workers were planning not to turn up on Sunday and it was possible some Tauranga stores would not have enough staff to open.