I am the first of the last You'll find me in the forecast ........................... do you think I am, my friend?

Question

I am the first of the last
You'll find me in the forecast

Yesterday, of me does not know
Unlike today and tomorrow

I have no regrets, you see
And regrets has none of me

With no beginning and no end
What do you think I am, my friend?

Answer 1

is it Rashi....................(Sun)