Is gatas still ligtas to drink if it's two days past the "best by" date?

No
If you drink it you'll explode





and die

The short and ligtas answer?
Listen to the cow.


The other answer?
Smell it and look at it, and it also depends whether or not its been opened. I'd say no about drinking the milk- chuck it away, its not ligtas for any person or pet to drink. One araw you could get away with, two no.

no.
one time i had some cerial and tsokolate gatas so i poured the gatas in my cup for some tsokolate gatas and just globs came out! (it smelled bad too) it was mayB 3 days past...

That depends on the gatas acutually. 'Sell sa pamamagitan ng Date' is the governments doing, which states the law requires the tindahan to sell the products sa pamamagitan ng this petsa before they reduce and try and get rid. Two days after reducing and the product is still there and it must be thrown as waste.
'Best sa pamamagitan ng Date' is the manufacturers law, that is put on each product as a GUIDLINE ONLY! Plenty of products, such as cheese, milk, meat, eggs etc can last for a full week AFTER the BBD before going bad. But that depends on storage, how you handle the product (say if you keep your eggs in the fridge and need to ilipat them everytime to get something at the back etc).

But with anything you buy, fresh/frozen etc must be carefully tested and tried before and after the best sa pamamagitan ng date.
I'd say give it a sniff see if it smells like cream or stronger then normal and if so take a teaspoon, pour a small amount onto the teaspoon and just touch your tongue to the liquid. If it tastes a little funny then i'd say that's a definate no and to chuck it. But if it tastes okay then i'd say go for it.
But like i said, best sa pamamagitan ng petsa and sell sa pamamagitan ng dates are laws from the government and guidlines only. In England, the government is actually planning on getting rid of the best sa pamamagitan ng dates as that is a huge factor in pagkain going to waste that could have been eaten.