I never saw a diode datasheet specifying a "Reverse bias saturation current". In my understanding, it's a parameter of a simplified
diode model rather than an empirical property. If you are intending calculations based on a particular diode model, you have to
extract the parameters from real diode data (find a parameter value, that fit's the real behaviour).
The problem is however, that you'll rarely find typical values of reverse characteristic in a datasheet. Most manufacturers
give only maximum values.