Two important minhagim to quickly mention.
- Before the start of Shemoneh Esrei (the silent Amidah prayer) an appointed member of the synagogue committee will announce either “Ya’aleh Veyavo” if it is the frist day of Rosh Chodesh (in a two day situation) and “Rosh Chodesh” on the second day, or if there is only one day.
- In the Mussaf Shemoneh Esrei there is no addition made during a leap yare, save for the actual leap month when “Vechaporas Posha” is added.
Regarding the standard minhag used throughout Ashkenazic Jewish communities- which is to add the words “vechaporas posha” from the beginning of the leap year, there is, to my mind, a very simple question:
How does one know on Rosh Chodesh Cheshvan whether this February there will be an additional month added to the Jewish calenadar? Did everyone look it up? Wouldn’t it be appropriate and necessary to have a sign in the shul to this effect? And doesn’t the lack of the sign connote that this once wasn’t the precailing practice?