The chief rabbis of Israel called this week on secular Jews to join their religious brethren in fasting on Tisha Be'av as a way of showing solidarity and unity at a time of war. "Those brothers and sisters who usually do not fast should make a special effort to do so this year to express the pain of those adversely affected by the war," wrote Ashkenazi Chief Rabbi Yona Metzger and Sephardi Chief Rabbi Shlomo Amar. The fast begins at sundown on Wednesday night and ends on Thursday at about 8 p.m. "The Israeli nation is connected one to the other by mutual responsibility, the rabbis wrote. "On this day, a national day of mourning, it is especially important to show and express our pain and hurt over the dissension that caused the destruction of the Temple." In contrast, within Reform and Conservative Judaism there are differences of opinion on whether to fast and if so for how much of the day. Rabbi Meir Azari, of Tel Aviv's Reform Beit Daniel Synagogue, said he would not fast. Azari, who said he was expecting about 300 people to attend the reading of Lamentations, prayers and classes, does not view Tisha Be'av as a day of mourning. "The destruction of the Temple was sad," he said "but it was part of the historical development of the Jewish people. We have to give the day meaning for contemporary Jews, for instance to understand that extremes in any direction - secular or religious - are bad. The rebels of Masada or the followers of Bar Kochba are not relevant. Rather it was someone like Rabbi Yochanan Ben Zakkai, a man willing to compromise, who secured the future of Judaism. "I won't go to a movie or a coffee shop, like many Tel Avivans, but I am also not going to fast." In Conservative Judaism, rabbinical students and some laymen adhere to the Orthodox strictures of Tisha Be'av, which include refraining from bathing and from wearing leather shoes. But there are two opinions regarding fasting, according to Rabbi Tzvi Graetz, of Shevet Ahim Congregation in Gilo, Jerusalem. "The first opinion is that one must fast the entire day," said Graetz, who will preside over an egalitarian prayer session of about 300 at Robinson's Arch, near the Western Wall. "But the other opinion believes that the fast should last only until midday, otherwise it appears as though we are oblivious to all the goodness God has bestowed on us. "Today we have the State of Israel, we have a Knesset, Jerusalem is rebuilt. We must recognize this change since the destruction of the Second Temple and acknowledge it in practice."