Now it's that time again, and we wish you a "Happy New Year".

In the last few weeks we have looked back and remembered beautiful and hopefully only a few not so beautiful moments.

We have made good resolutions, forged plans and ideas for the coming year.

At midnight between December 31st and January 1st it happens: The old year ends and the new one begins.

But why do we celebrate New Years on that night between December and January?

A New Year celebration in summer would be much nicer.

It's still reasonably warm at night and the sun doesn't set that early.

The school year ends in summer and everyone goes on vacation.

So why do we not celebrate New Year on the night of July 31st to August 1st but in the middle of winter?

To shed some light on these questions, let's travel back in time - first of all to the year 1582. That is the year our calendar was born today.

At that time, Gregory XIII.

Pope of the Roman Catholic Church and therefore one of the most powerful people in the world.

Gregor also had many scholars at his court, and they had been brooding over a problem for a long time: the years in their calendar were too long.

But what does that mean?

The calendar year has been based on our sun since ancient times. A year is the period of time that the earth needs to go around the sun - even if at that time many people still thought that the other way around, the sun rotates around the earth. The real problem with the solar year, however, is: A solar orbit around the earth takes almost exactly 365.2422 days.

Since 0.2422 days are difficult to accommodate in the calendar, a decision was made in ancient times for a leap day, i.e. an additional day in the calendar every four years. With such a leap day, a calendar year then lasts an average of 365.25 days. The calendar year is therefore a bit too long in relation to the solar year of 365.2422 days. At the time of Pope Gregory, this small difference of about 0.01 days meant that the beginning of the year had already shifted by ten days in relation to the sun. If it had continued like this, we would actually have been able to celebrate New Years sometime in the summer.

Pope Gregory and his mathematicians prevented this by coming up with the following: The year 1582 was shortened by ten days without further ado.

Thursday, October 4th, 1582, was followed directly by Friday, October 15th.

In addition, they stipulated that certain years do not have a leap day in which, according to the four-year rule, a leap day should actually be inserted.

As long as Pope Gregory's calendar system is valid, we will probably always celebrate the New Year in winter.

From the lunar to the sun calendar

Our journey to the year 1582 made it clear to us why the new year will probably continue to begin in winter. But we still don't know why New Year was celebrated in winter even then. So we have to go further back in time, to the year when a man named Gaius Julius Caesar introduced the calendar that Gregory later reformed. This happened in 45 BC, when that very Caesar was dictator of the Roman Republic and thus, among many other things, was able to determine the calendar.

Caesar had scholars too, and they too had noticed a problem with the calendar of that time.

It was a problem that many bright minds had puzzled over: There are three regular events that make us humans feel like time.

These are the alternation of day and night, the waxing and waning of the moon and the longer and shorter days as the sun orbits the earth.

The old Roman calendar tried to mathematically combine all these three events.

Unfortunately, this does not work with the orbit of the earth around the sun and the phases of the waxing and waning moon.

Caesar therefore opted for a radical approach: his calendar disregarded the phases of the moon and was based solely on the sun.