Julius Caesar introduced the Julian calendar in 45 BCE
because he wanted a more standardized system for
commerce and tax collection for his vast empire.
The Julian calendar replaced the older Roman calendar.
The Roman calendar was problematic because it was
based on the phases of the moon. The moon's cycle of
phases (29.5 days) didn't line up evenly with a solar year.
It required a group of people to decide when days should
be added or removed to keep the calendar in agreement
with the seasons, equinoxes, and solstices.
The Julian calendar used more advanced astronomical
observations to merge these two cycles. It had a year of
365.25 days, based on the solstices, with the days divided
into twelve months. It also included a "leap year" where
one day is added to the month of February in every year
divisible by four.
How was the Julian calendar more accurate than the
Roman calendar? Check all that apply.
It was based on the phases of the moon.
It measured a year as 365.25 days.
It required a group of people to decide when days
should be added or removed.
It added a day in February every four years.
It incorporated advanced astronomical
observations.