Julian Calender. Julian dates (abbreviated jd) are simply a continuous count of days and fractions since noon universal time on january 1, 4713 bc (on the julian calendar). To easily calculate gardening dates, use julian numbers in your calculations.
The julian calendar is named after julius caesar, during whose reign it was adopted by the roman empire, and is, essentially, the calendar we use today, excepting the minor. To easily calculate gardening dates, use julian numbers in your calculations.