New custom page on first login

We have the following requirement for a business scenario:

At the start of every quarter/half-year for 10 working days, we want to open a custom page where user views and confirms data on the first login.

So basically above we need to conditionally display a custom page to a user for a certain frequency.

I need to know where shall I put this code where I can check for certain conditions and then display the custom page to the user on first login if needed.

Any help would be highly appreciated.

Regards,

Nirmal