A brother assumed his parents ate suhur before fajr so he followed along & didnt bother checking the time. Days later he realized they ate after fajr, are his previous days valid? Today, to prevent issues, his parents getting mad, & insulting him, he chose to eat after Fajr, is his fast valid?

Ustadh AbdulAziz al-Haqqan

You must be sure and do the necessary means, so if there was no heedlessness and it was an honest mistake then the fast is valid, otherwise no. As for eating intentionally after fajir, how is that! Subhana Allah, the fast is invalid without a doubt.