It is fairly well understood that the library found at Qumran was associated with the temple in Jerusalem in some way, partly through the list of priests and their times of service, partly through the use of the sun-based calendar to set the temple services, and partly through the golden mirror that reflected into the inner chamber only on the day of the Spring equinox. That there was an observatory on the roof of Solomon’s temple is less well known, and that an entire tribe (Issachar) located in the Galilee area was devoted solely to astronomy who started the trend of wearing black robes with the moon and stars embroidered on them is really not known at all.
Daniel was a trained astronomer/astrologer of such skills that he was better than all the older men who served directly under King Nebuchadnezzar. Where else did he get his training, if not in the temple? He was taken captive in Jerusalem.
Just because the temple was run according to the Qumran calendar does not mean that the two are the same, however, because they are not.
The pattern for the tent and then the temple built on the same plan is common to both Egypt and the northern territories above Jerusalem. The rotation of the priestly courses is based upon that in the temple of Amen in Egypt. A lot of the customs of the Israelites are common to Egypt, some to the detriment of the people who practice them.
For instance, the mikvah, the immersion pool of the Jews is a custom from Egypt where it was practiced from the beginning mists of time, but when it was transplanted to Israel, there is an organism in the water there that enters the brain through the eyes and nose that attacks the brain and kills the person, yet the practice was still common in Qumran.
The practice of burying human feces was transplanted from Egypt to Israel, but there is an organism that thrives in the earth that is killed by the sunlight when the feces is left on top of the ground, yet the people continued to bury their waste until the “outhouse” was brought into use.
The calendar is not the temple, and the temple is not the calendar. The calendar was one of the tools used in the temple, but is is not the ruler of the temple. They are entirely separate.