Where we are in Texas we describe spring break as being the second week or first full week of March. This year it was the 10th, next year it will start on the 9th, and the 8th the year after that. Back in 2022 it started on the 7th which is why I specified full week previously.
DD is now 6 and in school but DW actually works for the school district and so to mitigate her taking time off when students are in school we typically follow the school calendar for trips ourselves. Since we get plenty of hot and humid in the Houston area we don't even consider summer trips, leaving Spring Break, Thanksgiving, and Christmas. While we love the holiday theming, we often choose Spring Break because of the crowds.
We have gone over Spring Break several times including 2015, 2020, 2022, and 2025. We always arrive late Thursday/early Friday the week before Spring Break officially starts, so March 6th this year, and check out the Saturday at the end of Spring Break. That gives us 8 park days Friday to Friday and without fail the crowds are noticeably larger at the end of those trips than the beginning.
Hope it helps and enjoy whatever you choose.