That's just the first date the camps took prisoners, my guy, you could argue quite easily that the genocide started sooner than that, during planning. Or, like many historians, you could say the genocide didn't start until the explicit goal of the final solution to the Jewish problem was decided upon and the Holocaust began in ernist, which would be in 1941.
There's plenty of documentation for what the Isrealis have done, your shitty argument was that because we couldn't agree on an exact start date there must be no genocide. That's a stupid position.
I am glad you read the wiki of the holocaust. Having done that, you now know you were wrong, governments actually do document their crimes, and dates can be pointed to.
Why not read the wiki for your genocide and then tell me what dates the documents are showing you.