The phrase "historic day" means a day that is very important and will be remembered in the future because of its significance or impact on history. Full definition
That makes it a minor historic day in British politics. (politics.co.uk)
We caught up with Victoria Pendleton, Laura Trott, the Brownlees and Sir «Incredible» Chris Hoy at the end of a truly historic day for the British Olympic Team. (teamgb.com)
Los Angeles Unified Superintendent John Deasy, who was the first witness to testify on behalf of the students in the eight - week trial, said: «This is a truly historic day for our education system. (laschoolreport.com)