The "Hashem, Hashem..." verses, which are the core of the atonement process.

Some observe a partial or full fast until nightfall.

: Detailed legal summaries and customs can be found at Shulchanaruchharav .

On the day of Yom Kippur Katan (the day before Rosh Chodesh):

: A liturgical poem often attributed to Leon of Modena. When Yom Kippur Katan is Not Observed

Every link he clicked led to a "404 Not Found" or a generic modern reprint. The digital world, it seemed, had forgotten the specific melodies and marginal notes his family once cherished.

: It is a time to atone for the sins of the previous month, allowing one to enter the new month with a "clean slate".