What term describes the calendar days that are sequentially numbered through the year from 1 to 365?

The term that describes the calendar days sequentially numbered through the year from 1 to 365 is known as the Julian calendar. The Julian calendar, established by Julius Caesar in 45 BCE, was one of the earliest attempts to create a consistent solar calendar. It divided the year into 12 months, with a system that included leap years every four years to account for the extra quarter of a day in the Earth's orbit around the sun.

The Julian calendar laid the foundation for how we understand the flow of days in a year, utilizing a straightforward sequential numbering approach that allows the days to be counted clearly from 1 to 365. This method helps coordinate agricultural, religious, and social events, providing a framework that has influenced subsequent calendar systems, including the Gregorian calendar, which refined the leap year system to improve accuracy over time.

Other options present different types of calendars: the lunar calendar is based on the cycles of the moon, the Gregorian calendar is a modification of the Julian calendar, and the fiscal calendar pertains to financial accounting periods, thus not fitting the context of counting sequential calendar days.