I have created a PDF fillable form for a loan contract and has 3 text filed

• Field 1 Name is Tenor
• Field 2 Name is Start Date
• Field 3 Name is End Date

I want to automate the end date by entering the tenor and Start date

Eg: if the tenor is 12 Months, Start Date 18/10/2021, end date should automatically appear as 18/09/2022