UPDATE: Original (~45AD Biblical Pre Julian) 13-month, 28-Day calendar that 1752 12-month calendar derived from, 7th month is confirmed to be September (i.e. "Sept" prefix which means 7), and the 17th of the month was always a Tuesday. 1st month was March, and pre April 1st was the "intermission" of 1 day every year and 2 days every fourth year with Christ's resurrection (i.e. Easter) celebrated April 1st (corrupted now into "April Fool's Day" to literally mock God).

1 MARCH [NAMED AFTER MARS, 4TH OF MAR ORIGINAL INAUGURATION DAY WAS AT THE START OF THE YEAR, vernal equinox at end of March]

[Intermission 1 day every year, 2 days every 4 years, for Easter celebration]

2 APRIL [April 1 was likely Easter celebration of Christ's resurrection]

3 MAY

4 JUNE (originally Quattilus, meaning 4th in Latin)

5 QUINTILUS (JULY)

6 SEXTILUS (AUG)

7 SEPTEMBER

8 OCTOBER

9 NOVEMBER

10 DECEMBER

11 UNDECIMBER (#11 HIDDEN FOR OCCULT PURPOSES?)

12 JANUARY

13 FEBRUARY (TRADITIONAL 'CLEANSING' FESTIVALS AT YEAR END)

Fixed order with March first. 28 x 13 + 1 = 365 days