Hd (od 21:00) -

Depending on where you saw this in a report, it could also refer to:

: Reports or tests for sleep data are often marked as "invalid" if the user does not wear the device or if the data is recorded outside this specific 21:00 to 09:00 timeframe. Other Potential Contexts HD (od 21:00)

: A television program or sports match scheduled for a High Definition (HD) broadcast starting at 21:00 . Depending on where you saw this in a