Tiny questions with quick answers - continuing thread

Are these both correct? If so, why is one fore (which I expected) and the other bore?

Dw i’n hapus i gerdded i’r ysgol efo chdi fore dydd Llun.

Be’ ti’n mynd i neud bore dydd Sul?

And for a bonus question, I’ve seen the “dydd” skipped, e.g. Saturday morning as “bore sadwrn”. Is that common, and if so is it more common in a particular region? Or does it change the meaning subtlety?