A time window defines the simulation start and end dates and times for a simulation. When creating time windows for cross section based simulations, the time window has to be set to match the time series time window of the data in the HEC-DSS file. For HEC-DSS time series data, the time window can be set to a subset of the length of the time series, but it cannot be extended on either end of the time series. When creating time windows for gridded data everything is set relative to the start time of the time window since the gridded data does not contain date time information. However, the simulation time window should contain the full length of time used by the hydraulic simulation to compute arrival time grids, if life loss is being computed by the HEC-FIA project.
When creating time window(s) for reconstruction computes, there are two options. The first option is to create a time window for each individual event, following the time window requirements for HEC-DSS time series data described above. The second option is to use the same time window for a subsequent event, but from the Simulation Manager dialog box set a simulation start offset (in days) for different events utilizing the same time window. The option to set a start offset is only offered for reconstruction computes and is available regardless of using the same or different time windows for each event.