Hi Dhivya,

It depends a bit on how much you want to adapt. If you adapt your process a bit you could probably use the default "Warnings" option for the sales module. If you really want the dates and as you do it now you'll need custom development.

If you activate this option "Warnings" you can set warnings on all products (under the tab notes on the product form) within Odoo which are shown on the orders. There is however no start and end date range in place there. You could import all the messages as warnings on the sale orders and do this process once every season. If that doesn't work you have two options. Either you create an automated action that automatically removes - or updates - the warnings or you create a custom module to support this logic, with date ranges.

Regards,
Yenthe