Israel doesn't mark today. They picked another date to go with their ideology.
http://www.haaretz.com/jewish-world/the-jewish-thinker/.premium-1.639209
"Ultimately, in 1951, Israel's Yom HaShoah (literally, Holocaust Day) was scheduled close to the anniversary of the Warsaw Ghetto uprising. The choice of date was an attempt to focus on those who fought against the Nazis, rather than on those who never had that chance. Those who "went like sheep to the slaughter," as it was phrased in those days, were an embarrassment to the so-called "new Jews" of Israel. The official name of the new memorial day—Holocaust Martyrs' and Heroes' Remembrance Day—reflected this mindset: It was, in large part, a commemoration of the lucky few who had been able to fight, rather than the unfortunate majority. In effect, Israel's version of Holocaust memorial day was not a commemoration, but a denial of memory. "
http://www.haaretz.com/jewish-world/the-jewish-thinker/.premium-1.639209
"Ultimately, in 1951, Israel's Yom HaShoah (literally, Holocaust Day) was scheduled close to the anniversary of the Warsaw Ghetto uprising. The choice of date was an attempt to focus on those who fought against the Nazis, rather than on those who never had that chance. Those who "went like sheep to the slaughter," as it was phrased in those days, were an embarrassment to the so-called "new Jews" of Israel. The official name of the new memorial day—Holocaust Martyrs' and Heroes' Remembrance Day—reflected this mindset: It was, in large part, a commemoration of the lucky few who had been able to fight, rather than the unfortunate majority. In effect, Israel's version of Holocaust memorial day was not a commemoration, but a denial of memory. "