Predicting that when they say "Spring", they mean sometime in March (March 20th is the first day of Spring)
April 12 2025 is after Easter, and I doubt they'd keep it closed during that weekend
April 12 2017 was the resort's 25th anniversary, but the promotion started in March of that year
March 6th 2022 was the start of the 30th anniversary celebration
"Swing Into Spring" started in March as well on the years that they did it
March, as noted, is this park's anniversary, with its own 25th happening in 2027