Can someone instruct me how to do the data calculation in Mendix. Specifically I have 2 attributes of type string. When the user enters the date for the first attribute (applicationDate) I should get the 15th day of the following month (example: user entered - 28-03-2021, I should get back 15-04-2021), for the second attribute (firstInstallmentDueDate) it should always return today. Attributes are of type string because that is how it must be in JSON. EDIT: Can someone instruct me how to do the data calculation in Mendix. Attribute applicationDate should be calculated in relation to current time (if for example currentTime is '2021-06-06', applicationDate should be '2021-07-15', in fact, applicationDate should always be the 15th day of the following month)
Kindly Have look, Hope it will be helpful for you.
I would recommend you to go through the Mendix documentation for date time Fucntions :
Secondly if i am doing this task I would prefer having two atributes one for User Interaction which is a Date time Attribute and Secondly String attribute for passing to JSON.
When ever the user is changing the value put a onchange flow or do a chnage object in the save microflow and do the Date time cacluclation and set it to string attribute using date Time Functionions like FormatDateTime( Date→ String).
For your second case you can follow the same two attribute FirstInstallmentDueDate- DateTime Attribute and FirstInstallmentDueDateSTR – String. So that you can keep the Default value of CurrentDate time for the DateTime Attribute which suffice for your second use case.