What happens if I change the monitoring station time?

Moving the clock forward will have no impact on up.time monitoring but will cause a gap in performance data when running historical reports.  It may appear that data is missing for the period of time represented by the time change but it’s really just a logical gap in the timestamps for newly collected data.  For example, if you moved the clock from 12 PM to 2 PM, you would appear to have a 2-hour gap in data collection when in reality, it’s only the clock changing.

Moving the clock backwards will cause a gap in data collection and service monitoring.  Each up.time monitor logs a timestamp of the last time it ran to determine if (or when) it needs to run again.  For example, if a monitor ran at 2 PM and you change clock back to 12 PM, the monitor will not run again until the clock once again reaches 2 PM.  This gap is deliberately created to avoid the undesirable alternate result of creating duplicate historical data, which would occur if the monitors were forced to start running immediately after the time change.

Note that both of these scenarios are temporary issues that occur only during the few hours between the original and new time settings.  Note also that changing the time on a target agent system will have no impact on up.time monitoring.