Thus – the first day of a month (Rosh Chodesh) is declared by the court by hearing the testimony of the witnesses, who saw the position and the shape of the moon.

Even if the court were to miscalculate and declare Rosh Chodesh to be on a wrong day – even if the court were to intentionally declare Rosh Chodesh on a wrong day – its declaration would be binding.

The Midrash tells that the angels ask G-d, “When is The New Year – Rosh Hashanah?”

“I do not know,” G-d responds. “Let us all go down to the earthly court and see what they have decreed.”

R’ Joseph B. Soloveitchik notes that the Creator has literally given some of His dominions to his people.
 

The New Year – Rosh Hashanah is the day when He judges us, yet we decide when Rosh Hashanah will occur!

This special power of the People of Israel sheds light as well on the Jewish view of holiness, says R’ Soloveitchik.

Holiness is not some magical force that appears on its own; it is something that we create through our deeds.

Man can imbue time with holiness and man can imbue objects with holiness. This is the special gift given to the People of Israel. 

Without our pure deeds, there would be no holiness.

And now a little bit of Hebrew:

The word MOED, (as used in the bible) – a special date usually for festivals.  

The word MOED is used in Modern Hebrew in several expressions.

For instance:

• The common blessing for festivals:

MOADIM LE’SIMKHA – Happy Holidays 

• The days in between the first and last days of Pesach and Sukkot 

KHOL HAMOED – Weekdays of the festival 

• The original date for taking a test 

MOED ALEF: (Lit. – first date) 

• The occasion of retaking the test – “remake” on a later date 

MOED BET:  (Lit. – second date)