The support team needs the ability to set a reminder on a particular issue. For example, to answer a client after some work been done, o a customer only got time at a specific date.

There is no such functionality in the HelpDesk app, but we created the special all for this purpose – Reminder for Jira (Marketplace Listing).

It's compatible with the HelpDesk app and might be convenient for your support team as well as for other Jira users.