Today in Eruvin (40), there was a detour into the prayers of Rosh Hashana and Rosh Chodesh. In olden times if a witness did not arrive on time for Rosh Hashana they kept the as a the Yomtov and prayed with a condition in the prayers stating that if today is Rosh Hashana or if tomorrow is Rosh Hashana.
The Rabbi says that this works because both are “zicaron’s” both mention “remember” in their prayers. Both prayers are therefore textually similar. Both Rosh Chodosh and Rosh Hashana are unique holidays because they occur on the first of the month, rather than the other holidays where they occur in the middle or later which gives time for the witnesses to come to Jerusalem and the Court to declare the new month. Rosh Hashana developed into a “yoma aricchta” (two days considered one) due to this uncertainty (safak). Both are susceptible therefore to “uncertainty” of when they occur.
However they share a greater uncertainty. According to the Shikker Dovid, the real uncertainty substantive. What will this year bring? Similarly, What will this month bring?. The unknown and uncertainty should humble us. The days are fraught with uncertainty, because our lives our uncertain.
The lesson of uncertainty is humility. The uncertainty of the date is a metaphor for the uncertainty in our lives. This thought should humble us, even if we are not ready for Rosh Hashana.