How far forward and back can the IPhone calendar go?

I was looking through my calendar at old dates and I wanted to see how far back it could go. I got to 1895 and then I got tired.
(1) how far back can it go?
(2) how far forward can it go?

And please no estimations or guessing.

I remember i tried to see how far forward it could go and got to 2500s. It took about 15 minuites

Got to 10000 got bored

Currently at 20014, getting bored already.

22015 and got bored but ironically the days and dates matches of 2015