You will start losing the oldest glucose readings if the reader is not scanned at least once during an 8-hour period. For example, you scan the reader over the Sensor at 13:00 and scans again at 22:00 then users will lose glucose data from 13:00-14:00. The reader will indicate this missing data on reports. There will be a gap on the Daily Trace that impacts the statistics on Sensor usage however it will not be indicated in other reports.