Professional Term Clarification

Hey to everybody, I hope English is not a problem as my Danish is still to weak to conduct a serious conversation. 

I have recently started up a company which will import some products from italy and Market them in Denmark. I have arranged everything with supplier, a shipping company, everything is ready to go. Now, i've gotten an email from my supplier in which i was asked something that i do not completely understand, and for sure i do not want to look stupid in front of them and ask them what do they mean about it, so Im asking community here if you can help me.

After receiving an offer from supplier, they have asked me to provide them with following, quote:

"For the documents, we need to receive, also, the fiscal date!"

Whad do they mean about it? Anybody?

Thanks

Forgot to mention, only call the Danish tax agency, if you company is danished based. Otherwise it is the fiscal date of the country(s), in which your company is registered.