The time step in this model is hourly.
To obtain the day, I look at the methods that are available in the HecTime class. I notice that there is a day() method available.
To get the details of this method, I look at javadocs (available in the installation of the HEC-ResSim software) under hec.heclib.util. From the figure below, I can see that this method returns the day of the month in integer format.
I now need to look at how to access this method for the current time step. Under the RunTimeStep class, I see a method termed getHecTime().
I look in hec.model.RunTimeStep in javadocs to get more information on this method and see that I can access the methods under the class HecTime by using this method.
In the code, I ask to get the day() method under the HecTime class by using the getHecTime() method under the RunTimeStep class. I also add a print statement to test what this is giving me.