Complex sentence: Several same-sex couples successfully applied for an exemption from the one-month waiting period between completing a notice of intended marriage form and the wedding ceremony, and the first legal same-sex marriage ceremony in Australia occurred on 16 December 2017.
Split into simpler sentences: Several same-sex couples successfully applied for an exemption from the one-month waiting period between completing a notice of intended marriage form and the wedding ceremony. Consequently, the first legal same-sex marriage ceremony in Australia occurred on 16 December 2017.