In January 2015, 26 of the 38 members of the International Anthropocene Working Group published a paper suggesting the Trinity test on 16 July 1945 as the starting point of the proposed new epoch.[21] However, a significant minority supports one of several alternative dates.[21] A March 2015 report suggested either 1610 or 1964 as the beginning of Anthropocene.[22] Other scholars point to the diachronous character of the physical strata of the Anthropocene, arguing that onset and impact are spread out over time, not reducible to a single instant or date of start.[23]