To understand the word of our Father YAHWEH, we must take everything like a grain of salt and constantly look for the truth which has been obscured so greatly through time.  With this in mind, the modern Hebrew Calender utilized by the Ashkenazi Jews as well as others is incorrect.  To understand this is to simply look at a few factors; namely the beginning of their New Year as well as the names of the months themselves.  Knowing the Israel was in diaspora in Babylon, many names in the modern Hebrew Calender utilize names of Babylonian and other deities.  Likewise, many modern Christians follow the Gregarian Calender which was implemented by Pope Gregory centuries ago.

The modern Hebrew Calender states that the New Year begins at Rosh Hashanah, proclaiming it to be the anniversary of the birth of Adam and Eve (Chawwah), however per Leviticus 23 the first month of the year is the month of Abib (which occurs around Spring).

Those whom follow the Gregarian calender do the same with this adjustment of the New Year given that historically January as well as February did not exist originally; being nameless with the New Year beginning in the Spring.  When they were incorporated, the calender changed a few times to which the New Year began on January 1st, then back to the Spring, and then back to January first with the implementation of the Gregarian Calender.  Validation of this is simple given the names of the months themselves:

September literally means the 7th month, however in the Gregarian Calender it's the 9th.  The same applies to October, November and December which in turn mean the 8th, 9th, and 10th month consecutively, however per the Gregarian Calender are the 10th, 11th, and 12th month.

Hence, we look to the scripture to find the accurate Hebrew calender, as it should be.  Without knowledge of the proper observance of the Calender, it makes it impossible to celebrate the 7th year sabbath of the land, as well as the 50th year Jubilee.