According to the ancient writings, we can check to see if we will live or die this next year by checking our shadows on Hoshana Rabbah. This is on the 7th day during the Feast of Sukkot.
When we stand in front of the moon, it is said that our shadow will reflect our life or death verdict for the coming year. For those who will not make it to the next Rosh Hashanah, they will lose their shadow after midnight on Hoshana Rabbah. Some say their shadow might be incomplete (i.e. missing a head) or they might not have a shadow at all where others do. It is only on Hoshana Rabbah that this can occur, the full shadow will be back the next day.
This is why many stay up all night the night before reading the entire book of Deuteronomy and then after midnight, they will read the entire book of Psalms, to try to correct their souls as much as possible. Some will study the Zohar all night long.
There is no verdict that can not be changed without self examination and real repentance.
Hoshana Rabbah is considered the "last chance" to repent and get right with our creator before the verdicts are delivered.