The movement that began in 1990 by a group of Texas students - and has been student-led ever since - has grown to an annual event that draws one million students across America and in more than 64 countries.
For King & Country singers Joel and Luke Smallbone promoted the prayer event in a video.
"This has always been something that has been close to me and my heart because I've been able to see the power of prayer and to be able to see when school students get together and surround that flag and be able to pray together, something real significant takes place," Luke Smallbone said, adding that he participated as a kid.
Many students plan their meeting at the flag pole at 7 a.m. and circle up, holding hands in prayer. Some gatherings include worship, Bible reading, and sharing, but all focus on one thing: prayer.
"It's not about making a statement," this year's promotion video says. "It's about prayer."
The theme for the event is a Bible verse from 2 Chronicles 7:14, according to CBN News: "If my people, who are called by my name, will humble themselves and pray and seek my face and turn from their wicked ways, then I will hear from heaven, and I will forgive their sin and will heal their land."
SYATP officials advise students, "You can legally gather for prayer before school, but it's best to let the administration know ahead of time."
The event is the highlight for the Global Week of Student Prayer Sept. 22-28.
Next week, students are encouraged to bring God's Word to their schools on Thursday, Oct. 3, "Bring Your Bible to School Day," which New Orleans Saints quarterback Drew Brees promoted before getting backlash from LGBTQ groups angered that Focus on the Family was sponsoring the event.