...
If the time zero is different then the icon will indicate that the available run is invalid. In systems which have a small cardinal time step this behaviour can be problematic because runs are marked as being invalid too quickly.
The element graceTime <graceTime> can be used to introduce a grace time for the time zero was used in a run. If the difference between the time zero for a node and the time zero which was used in the last run is less then the grace time then the run will still be marked as valid.
...