The first month of civil year is Tishrei, and that is also when the year changes, so please add another method to return that method of month counting (Tishrei=1). This is also consistent with the Jewish calendar in Excel.
Per Wikipedia:
Nowadays, the day most commonly referred to as the "New Year" is 1 Tishrei (Rosh Hashanah, lit. "head of the year"), even though Tishrei is the seventh month of the ecclesiastical year. 1 Tishrei is the civil new year, and the date on which the year number advances. Tishrei marks the end of one agricultural year and the beginning of another,[31] and thus 1 Tishrei is considered the new year for most agriculture-related commandments, including Shmita, Yovel, Maaser Rishon, Maaser Sheni, and Maaser Ani.
The first month of civil year is Tishrei, and that is also when the year changes, so please add another method to return that method of month counting (Tishrei=1). This is also consistent with the Jewish calendar in Excel.
Per Wikipedia: