Because Christianity existed BEFORE the Gregorian Calendar existance! Here is the timeline history for the Gregorian Calendar
Yes! All the history data of martyrs in Christianity (even since the time of NERO), MATTERS!
Furthermore, the time of Noah and the ARK is given in the HOLY BIBLE! God initiated this time to be specific based upon the signs in the heavens! Go ahead, look up the time when the Ark landed. It specifically says the month in which this happened! In the KJV it says "in the month of."
Ancient cultures have used various versions of -lunar-nature-seasonal- calendars. The Mayans even considered "planetary time" as an important factor in how they calculate things. The "morning star" has significance in the bible!
Please consider learning MORE about GOD's time based DIRECTLY from the bible and astronomy data.
Of course no man can truly "adjust" their heart to the gospel UNLESS they are familiar with the gospel message and various people of the bible. A "gregorian calendar" may be used to keep up with the needs to serve humanity, but in reality, people need redemption. People NEED to understand that JESUS was there in the beginning during the time of CREATION!
Further study can be found here: BIBLICAL HEAVENLY SIGNS
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