Select the Points tab in the Time function definition dialog to define the course of a function.
To define a time function, select it in the Functions tab, select the Points tab, and do one of the following.
To delete a point of the time function, select it and click Delete.
To change a point of the time function, select it, click Modify, and enter the values.
To delete all points of a time function, click Delete All.
To delete points of a time span, click Delete Span and define the time span to be deleted.
To save a time function to a text file, select it, and click Save to file.
To import a saved time function definition text file, click Open from file, navigate to the location of the file, select it, and click Open.