We've made some changes to our yahrzeit calendar feeds and integration with Google. We also now offer email reminders for yahrzeits and anniversaries. We invite you to come back to Hebcal and try the new feature!

Hi, thanks for the feedback!

In general, Jewish Holidays begin the evening before the date specified. This is because the Jewish day actually begins at sundown on the previous night. Sometimes, for clarity, the Erev holiday is also included to indicate that the holiday begins the evening before.

We choose to add the Erev for major holidays, but don't typically add Erev for a minor holiday like Tu B'Av.

https://www.hebcal.com/home/47/when-do-the-holidays-begin