Kidist Deneke is supposed to be seated in her first-period class by 8:45 each morning. But most days, the Roosevelt High senior is dropping off her younger sister at school then, before catching a bus to her own school.

She almost always arrives late, but it has never posed much of a problem — until now.

Deneke is a member of the Class of 2018, which approaches its final three months of high school in the shadow of a graduation scandal that has rocked District schools.

An investigation showed that one of every three graduates from the District’s public schools last year missed too many classes or improperly took makeup classes, undermining the validity of hundreds of diplomas. In the wake of that review, school administrators tightened enforcement of long-ignored attendance rules, meaning seniors with too many absences will not be allowed to graduate.

The graduation crisis cost four school officials their jobs and now leaves students such as Deneke, who thought they were on track to graduate, scrambling to figure out whether they can earn their diplomas on time.

Taahir Kelly, a junior at Roosevelt in Northwest Washington, said he never knew accruing 30 unexcused absences in a course would automatically result in a failing grade. He has eight older brothers who graduated from the school, and they also did not realize that such a policy existed, he said.

Since middle school, Kelly said, every academic term had played out the same way: Teenagers would miss class, complete makeup work and pass. That is changing.

Kelly said he and his friends think the school’s attendance policy is reasonable. But they object to the sudden enforcement and believe the city should have waited until at least next year to adopt the tougher policy.

“Students are getting penalized for having this mind-set, but they got this mind-set from school,” said Kelly, who does not have attendance issues and hopes to attend college on a track scholar­ship.

Deneke said she was informed by administrators near the end of the second term that she had been tardy too many times and could fail her D.C. history class — which is required to graduate — if she did not get her absences excused.

She got lucky; the late arrivals were excused. Other students, she and classmates said, are discovering they will not receive their diplomas. They want city leaders to realize that it is students who stand to face the steepest consequences over the graduation scandal and the stricter enforcement of standards for receiving a diploma.

“I feel really bad for the Class of 2018,” said Darrell Watson, a longtime music teacher at Ballou High School, epicenter of the graduation scandal. “They are working really hard. It’s almost like they are putting all the weight on their shoulders and are trying to prove a point.”

Latisha Chisholm, the special-education coordinator at Anacostia High, said that over the past month, she and other educators have had difficult conversations with students who no longer stand a chance of graduating in June, because they have already accrued 30 absences — the number that leads to failing a class. In her job, Chisholm says, she endeavors to help students come up with solutions to problems they face, but this time, there is little she can do to help some students reach the graduation stage on time.

Many of these truant students have stopped coming to class or have been disruptive in school, knowing that even if they complete their work, they will not receive their diplomas on time, Chisholm said.

She and other Anacostia staff members are rushing to connect with the families of children who have more than 20 absences to ensure they know they will flunk out if they reach 30 unexcused absences.

“They are being blindsided by this new crackdown of old rules they had no clue about,” Chis­holm said. “For the students who already have gotten 30 absences, it feels like there is nothing they can do, so there is a feeling of hopelessness among teachers and students.”

The school system is hosting events at high schools through March to make sure parents and students understand attendance and graduation policies and know what resources are available. D.C. schools spokeswoman Kristina Saccone said that more sections of core classes will be added for students needing to retake them to graduate. Students who cannot meet the requirements in time will receive guidance if they want to enroll in summer classes or alternative high schools.

The investigation of the graduation issue concluded that the District’s schools are plagued by a culture that encourages educators to hand out diplomas to meet lofty graduation goals even if that means giving a high school degree to a student who missed half the academic year.

After the findings were released, Antwan Wilson, who was schools chancellor, vowed that stricter adherence to graduation rules would take effect before the Class of 2018 graduates.

“Are you telling me that they didn’t know they were supposed to go to school?” Wilson said at a news conference last month, before he was swept up in a different scandal and forced to resign after he skirted school system rules to transfer his daughter to a sought-after school. “They know that they are supposed to go to school. You can have an attendance issue and not miss 30 periods of a class.”

The Roosevelt students say it is more complicated than that.

They are frustrated their school may have graduated some of their peers unprepared for college and the workforce. But they also are angry that the school system never sought student input as officials started more rigorously enforcing graduation rules midyear. They fear that no one truly understands the policies and that motivated students with difficulties at home that prevent them from showing up for school will be penalized for the school system’s failures.

Roosevelt students wrote a ­petition to school administrators calling on them to delay enforcement of the attendance rules and lamenting that school leaders had also been unaware of attendance policies — or ignored them. Dozens of juniors and seniors signed the letter. They also called on the chancellor to create alternative school schedules for students who have legitimate reasons for not being at school each day.

“Students were appalled they didn’t know what was going on,” said junior Jahara Abubaker, who helped write the letter.

Junior Kevin Hernandez said his cousin, a senior at Roosevelt, will have to go to summer school if he wants to graduate — a reality that has caused tension in the family.

“Just like we’re held accountable — my cousin has to go to summer school — adults should be held accountable,” Hernandez said. “It’s a two-way street.”

Benjamin Korn, a Wilson High senior who co-edits the student newspaper, said administrators did little to inform students of the attendance rules.

He said the introduction of more stringent enforcement of the policy complicated the college application process for some students because the school delayed the release of second-term report cards while it verified that attendance and grading policies were followed.

“It’s such a major policy change coming halfway through the year,” Korn said. “It’s really unheard of.”

The school system released midyear data last week showing that the graduation rate is expected to decline in 2018 — a sharp reversal for a system that has boasted seven consecutive years of increases. According to the data, 42 percent of seniors attending traditional public schools are on track to graduate, while 19 percent are considered “moderately off-track,” meaning they could still earn enough credits for a diploma.

Even if all of the students who are “moderately off-track” get diplomas, the graduation rate this year would still dip below last year, when it stood at 73 percent.

“Students are what we need to focus on,” D.C. Council member Trayon White Sr. (D-Ward 8) said. “We need to figure out a way to wrap our arms around the children so they can get a good education and have the community support.”

Students and teachers acknowledged that the culture around attendance needs to change, but they said administrators cannot expect it to change overnight.

“It’s impossible to change a culture in three weeks,” Chisholm said. “And that’s what central office has tried to do.”