According to the Christian calendar, Jan. 1, 2020 might not really be the start of the new decade.

With the excitement of ringing in a New Year this week, excitement is rising. But the hype surrounding 2020 and the start of a new decade is up for debate, some say.

While many believe Jan. 1, 2020 will be the first day of the new decade, others say we will not enter a new decade until Jan. 1, 2021.

The debate centres around time and its varying forms of measurement according to various calendars and markers.

Clarity in time and space?

Stars and space have long assisted in the telling of time and noting its passing. University of Winnipeg Physics Department Instructor Vesna Milosevic-Zdjelar has studied and taught on the subject of astronomy.

Milosevic-Zdjelar, whose research interests include astrophysical cosmology and galactic astronomy, says the argument surrounding when the new decade begins is "all arbitrary."

Many issues arise when trying to decide the definite time. Different cultures throughout history have told time in different ways depending on whether they use the sun, moon, or stars, Milosevic-Zdjelar says.

"It depends on who needs what."

Precision on the measurement of time passing is further complicated by the rotation of the solar system. One trip around the sun by the Earth takes roughly 365.25 days, an imprecise value that is not typically accounted for in an exact manner.

"Every four years we accumulate one extra day as opposed to the calendar that we have fixed to 365 days. And that little correction that is not .25 of the day but roughly .25 of the day accumulates also over a long period of time. So how do we measure it?," Milosevic-Zdjelar says.

According to Milosevic-Zdjelar, many methods for measuring this variance exist, but the basic fact we need to know for our day-to-day lives is simply that one turn around the sun is the equivalent to a year.

How we measure a year is another period of time that bears confusion, Milosevic-Zdjelar points out. The names of months in a year, for example, cause confusion when their Latin translation is taken into consideration.

"When you think of names like September, 'septo' means seven in Latin, October, 'octo' means eight and those are [the] ninth and tenth months in today's calendar, so something is off by two months," Milosevic-Zjelar says.

In Roman times, the New Year was on March 1 rather than January 1, the instructor explains, showing the reason behind the discrepancy in the names of the months.

The end of a decade

The differences amongst these varying measurements contribute to the difficulty in definitively naming the start of the new decade.

Astronomers still use the Julian calendar and Milosevic-Zdjelar says it all depends on "what people really want and when they started measuring something they needed."

The current measure of time is rooted in Christian culture. "When you count [on the] calendar from a date when Jesus ... was born, then it wasn't the year zero, it was the year one," says Milosevic-Zdjelar.

"So when you start your decade with year one, then you have to start this decade with 2021 and then end it with the year that ends on zero."

The ultimate conclusion Milosevic-Zdjelar draws: this year will mark the end of a decade and next year will signify the new start, according to the Christian calendar.

But Milosevic-Zdjelar doesn't believe it really matters when the decade starts. "If they want to start the decade now with zero, that's fine. If they want to start it with one, that's fine, too."

For the purpose of everyday life, filled with a mixture of cultures, the starting date for the new decade is, as Milosevic-Zdjelar says, arbitrary.