D.C. Public Schools pushed back its deadline for teachers and staff to submit coronavirus test results because of technical difficulties with its website and inclement weather that prevented some of them from heading to test sites.

The school system is requiring every teacher, staff member and student to submit proof of a negative test ahead of its in-person return date, scheduled for Thursday. Teachers and families from across the District started heading to schools to pick up rapid antigen tests Tuesday, with more pickup times scheduled Wednesday.

Teachers and staff were scheduled to turn in results by 2 p.m. Tuesday, but the online submission form was not allowing some of them to upload results and was still down as of 3 p.m. Tuesday. The deadline to submit their test results was pushed to 10 a.m. Wednesday.

Schools Chancellor Lewis D. Ferebee said that the system was working with the vendor to find a solution to the problem, although other alternatives were also on the table.

“As we’ve gone throughout the public health emergency … we’ve evolved and pivoted accordingly,” Ferebee said during a news conference Tuesday.

He added that it was too early for more information about the alternatives. For now, families should expect to upload results to the district’s site and that the system will be ready. If not, the system will notify families accordingly, he said.

D.C. Public Schools did not have data available regarding how many tests have been distributed across schools. At Lafayette Elementary School, where Ferebee met with reporters, roughly 800 tests were distributed to families and staff by Tuesday afternoon.

Officials have said any student who tests positive must quarantine for 10 days.