Here the fact that the New Testament was written in Greek is a big help. In the Old Testament the Most Holy was entered twice, first when they inaugurated the services at the completion of the tabernacle, then the temples. and there after the day of Atonement. In the Septuagint translators decided to make a clear distinction by using two different words. One word for when within the veil for the inauguration of the service at the start of the ministry there and a different word for entering on the day of atonement. (There is also evidence that Shavu'ot/Penticost is connected with both the giving of the law and the inauguration service).
Daniel 8:14 uses cyclic terminology, May I recommend "Before Philosophy" by Henri Frankfort and others from the archaeology department of Chicago University to explain ancient cycles. According to Leviticus 25 the Hebrew cycles are 6 days and the Sabbath, 6 months and Passover/Yom Kippur, 6 years and the Sabbatical year, and 6 Sabbatical years and the Jubilee. Thus we have 2300 days, half years, full years or Sabbatical years. Since Daniel is based on Deuteronomy and Deuteronomy has everything in the Jubilee in the Sabbatical year, our options for Daniel 8:14 is days, half years and full years.
Daniel 8:14 was given the year that included 2300 literal days to Belshazzar's feast. Ezekiel has a 2310 day prophecy connected to how the last 2310 days could have been of the 70 weeks had Jesus been accepted (and if you exclude the 10 days from the fall New Year to Yom Kippur, we have another application of the 2300 evenings-mornings prophecy).
1844 was ONE of the possible interpretations and applications of Daniel 8:14. I would not limit Daniel 8:14 to 1844, but it is inclusive of the text. And we find 1844 being the Sabbatical year (and if I recall correctly the Jubilee) when the church entered a new experience. On the one hand Evolution was becoming popular and before there were good and bad people but they tended to agree that there was a God and that the Bible was inspired. But now things were changing and Atheism was growing and people questioned the idea of inspiration and you had modernists who believed that the Bible was not inspired and the fundamentalists with an extreme view of inspiration. Historicism was being replaced by Dispensationalism. On the other hand the Rosetta stone was starting to be translated unlocking ancient languages. Robinson explored the Holy Land opening up serious (instead of traditions) studies in Biblical geography opening the door for archaeology and where we were able to investigate the pages of scripture like never before. 1844 was the Sabbatical (and Jubilee ?) year that enters this whole new cycle and experience. Why didn't the "Investigative Judgment" start before 1844? Because we are also talking about milestones in history with things that on the one hand there are gradual changes every day, but there are milestones where these gradual changes come together and we can make a distinction between events before and after. 1844 is one of these milestones and is also ONE of the days in the cyclic times that fit Daniel 8:14