Hello,

Thank you for reaching out here in the DocuSign Community.

To help you with the questions you asked, you need more information about your questions, for example what you are doing and how you are doing it.

I share information about the Date Tab

https://www.docusign.com/blog/developers/tabs-deep-dive-tab-types#:~:text=Date%20Signed%20and%20Date

Regards,

Eric | Docusign

Hi Eric,

We want to have validation on datepicker fields (using Date Tab). for example,
1. Date of birth cannot be in future.
2. If for some question there are 2 datepicker with start and end date - in this case end date cannot be before start date. 

We are using docusign API to create envelope and send it as email to user for signing.

Appreciate your help.