How long to register birth?

My wife brought her Slovak Certificate of Citizenship to the registry office in Bratislava along with applications to register her and our kids' birth, which was then sent to the special matruszka.

We were told that by law they need to process the births within 90 days, but I'm wondering what your experiences have been. Our Schengen area tourist visas expire at the beginning of November, so we're getting a little antsy, as 90 days would put us 7 days over the limit on our visa.