time won't let me

measuring time -- how do you count the "days on a calendar"

WHERE do you begin ?
What day or year was "zero" ?

julian day the Julian Day is the unit of a chronological system, created by Joseph Scaliger in 1582, in which any date is measured by counting the number of days from an arbitrary zero day -- January 1, 4713 BC, at Noon, GMT. It is now use mostly in astronomy to calculate the number of day between two widely separated periodic events such as eclipses.
The Julian Day ( JD ) of Jan 1, 1980 ( at noon ) = JD 2, 444,240.0
Jan 1, 1990 ---- JD 2,447,892.5
Jan 1, 1992 --- JD 2,448,623.0
Jan 1, 1996 --- JD 2,450,084.0

Julian Period
a time period of 7,980 Julian years used, chiefly by astronomers for counting back over long periods of time to determine how many days separate any two events.
Each day in the Julian period is consecutively numbered from the beginning of the period ( Jan 1, 4713 BC ), so that the number of days between two events can be calculated simply by subtracting the Julian number of the first event from that of the second event.
the period of 7,980 years was chosen because it is the product of the numbers of years in the solar cycle ( 28 ), lunar cycle ( 19 ), and the Roman cycle of indiction ( 15 ). The Julian period was proposed by Joseph Justus Scaliger in 1582 and named in honor of his father.

5 / 5f / 95
11 / 15w / 95