Based on the search results, there is no information about which Jewish holiday is today. However, it is important to note that Jewish holidays begin at sunset and end at dusk on the last day of the holiday. It is also important to note that the Jewish calendar is based primarily on the moon (lunar), with periodic adjustments made to account for the differences between the solar and lunar cycles. Therefore, the dates of Jewish holidays change every year and are not fixed to the Gregorian (civil) calendar.