Hi Zulfikarlos,
The PRATE function will only work properly on the rule that is called through the function P0014 & P0057.
This PRATE will prorate based on the calendar days.
In our case we have created a rule after the Processing of Time data schema.
Then in our custom processing class created a new parameter 'Prorate IT0014'
If a wage type is marked with that parameter the following rule is processed
Please go through the documentation of the operation PRATE and validate if it is suitable for your requirement.
Thank you
Viswa