What are the details of the new OPM “Delayed Arrival” announcement?

OPM will announce a designated time by which employees should report to their duty location. All Tier II and III non-emergency employees who commute to their worksite on that day are expected to arrive no later than the designated time and will be granted excused absence (administrative leave) up until that designated time. If an employee arrives after the designated time, he or she will be charged leave. If unscheduled telework is announced as an option, employees who choose this option should telework for their entire tour of duty. If unscheduled leave is announced as an option, employees who choose this option will be charged leave for their entire tour of duty. Tier I emergency employees are expected to report on time for their usual tour of duty, unless directed otherwise.