5.6 Simulation Time Settings

5.6.1 Command Status

Required.

5.6.2 Description

Simulation time settings define the temporal framework for a TUFLOW FV model including how time is formatted, interpreted, and applied across inputs and outputs. These settings control the simulation start and end times, establish the reference time datum and ensure consistency when reading time series data or writing results.

TUFLOW FV supports ISODATE and HOURS formats and these are set using the Time Format command. Supported simulation time setting model implementations are summarised in Table 5.8, with links to the relevant implementation sections below. Time setting commands are listed in Table 5.9. The selected format must be applied consistently across all control files and time series inputs.

Simulation start and end times are specified using the Start Time and End Time commands, using the chosen time format.

Table 5.8: **Simulation Time Setting Model Implementations**
Model Implementation	Description
Hours	Model times are specified in decimal hours.
ISODATE	Model times are specified in dd/mm/yyyy HH:MM:SS datetime format.

Table 5.9: **Simulation Time Setting Commands**
Command	Description
Start Time	Required - Specifies the start time for the simulation.
End Time	Required - Specifies the end time for the simulation.
Time Format	Optional - Sets the format of time to either decimal HOURS or ISODATE (dd/mm/yyyy HH:MM:SS).

5.6.3 Hours

Using this method model times are specified in decimal hours relative to 0.0 hrs. This is the default simulation time settings implementation.

! Time settings using the HOURS time format
Time Format == Hours ! {Hours} | ISODATE
Start Time == 0.0 ! Simulation Start Time (Hours)
End Time == 3.0 ! Simulation End Time (Hours)

5.6.4 ISODATE

Using this method model times are specified in dd/mm/yyyy HH:MM:SS format. This implementation is useful if running models for specific hindcast periods or when needing to calibrate models to observed data.

! Time settings using the ISODATE time format
Time Format == ISODATE ! {Hours} | ISODATE
Start Time == 01/01/2015 00:00:00 ! Simulation Start Time (dd/mm/yyyy HH:MM:SS)
End Time == 01/02/2015 00:00:00 ! Simulation End Time (dd/mm/yyyy HH:MM:SS)