This information is up to YOU as the reader to decide the TRUTHS. Using the Qumran calendar to coordinate with astronomy MAY possibly vary from person to person, but still allows for similar understanding to that of the modern day Jewish Calendar. Often times there is a TWO week delay in time between Qumran Calculations and modern day Jewish calendar calculations. Reason: The first day in the month of ABIB in the Qumran calendar is a full moon in the first cycle while the modern day Jewish calendar uses the sighting of the sliver of the moon.
A key thing to know and remember: 9th of Ab is a little over 58 days from the Day of Atonement (60 Days) on any calendar. Jews continue to this day to remember (Tisha B'Av). Exactly 58 days before Feast of Atonement, according to the Qumran Calendar this year, is the Solar Eclipse that darkens the moon from the 6th hour to the 9th hour (noon to 3:00 pm similar to event when Christ was on cross: Luk_23:44 And it was about the sixth hour, and there was a darkness over all the earth until the ninth hour.).
The top picture shows the event in AD 31 where Christ could have been on the cross and suffered for sins using Qumran Calendar calculations as the sun could have been darkened from the 6th hour to the 9th hour for more information click (When Did Jesus Rise from the Grave) or (First Fruits today vs. AD 31)
The bottom image are the events that will be unfolding in the heavens as we enter the fall feasts. Notice how the planets highlighted as well as the sun and moon represent the -seven golden candlesticks on menorah-
For more information about this topic try studying the Qumran Calendar: (Conversion of Qumran Calendar to Metonic Cycles)
Or for more detailed understanding try studying the calendar according to biblical events and the Qumran Calendar in depth: (Biblical Heavenly Signs)
For a detailed article about WHY astronomy matters when it comes to Christian faith....... read this article and MEDITATE on the design of the tabernacle as described in the LAW. Tabernacle is Designed with Astronomy in Mind