sentence: official birthday and coronation day of the king of tonga ( tonga ) procession of the cross and the beginning of dormition fast ( eastern orthodoxy ) statehood day ( colorado ) the beginning of autumn observances in the northern hemisphere and spring observances in the southern hemisphere ( neopagan wheel of the year ) : lughnasadh in the northern hemisphere , imbolc in the southern hemisphere ; traditionally begins on the eve of august 1 .