EU Citizens - Residency - Minimum Number of Days in Portugal Per Year

Hello,

I have Canadian and Irish citizenship. I am thinking about moving permanently to Portugal.

I know this is reasonably straightforward because I have an Irish passport (no visa required, etc). I have to officially declare my intention to seek residency soon after arriving.

Here is my question: Once I have made the declaration that I wish to seek residency, how many days per year do I have to reside in Portugal in order to ensure that my residency request remains valid? The final step for me would be to obtain Portuguese citizenship.

I am mostly asking because I would like to spend some time travelling to other European countries.

I have not been able to find out from any of the sources I have consulted what the rule might be.

Thanks.

John