Does it really take 40 - 60 hrs to polish a windshield?

[PepeLoco]

My windshield is original, the frame has quite a bit of rust at the bottom. Replacing the frame and glass is on my list of things to do; when money becomes available.

Until then, I thought of polishing it. But does it really take 40 - 60 hrs? Is it really that difficult? Which is the best way/product?

I do have a deep scratch from the wiper that I am not sure I can get out, but the millions of little ones I need to get out due to the glare at night.

Thanks!
Pepe