they are called Nowruz and Yalda. Nowruz is a 40 day celebration of the Winter Solstice and has been celebrated since the time of Zoroasterianism.

The Other is called Yalda and is a rite of the Mithraic religion. These are both ancient religions that predate Islam. Zoroasterianism is 1000 years older than Islam.

http://en.wikipedia.org/wiki/Yald%C4%81

Yalda (Persian: یلدا) , Yalda Night / Shab-e Yaldâ (Persian: شب یلدا), or Shab-e Chelleh (Persian: شب چلّه, meaning "night of forty", Azerbaijani: چله گجه سی ) is the Persian Winter Solstice Celebration[1][2] which has been popular since ancient times. Yalda is celebrated on the Northern Hemisphere's longest night of the year, that is, on the eve of the Winter Solstice. Depending on the shift of the calendar, Yalda is celebrated on or around December 20 or 21 each year.

Yalda has a history as long as the Mithraism religion. The Mithraists believed that this night is the night of the birth of Mithra, Persian angel of light and truth. At the morning of the longest night of the year the Mithra was born.

[ame] http://en.wikipedia.org/wiki/Nowruz [/ame]

Nowrūz (Persian: نوروز, IPA: [nouˈɾuːz], originally "New Day") is the name of the Iranian New Year[4] in Iranian calendars and the corresponding traditional celebrations.[5] Nowruz is also widely referred to as the Persian New Year.[6][7][8][9]

Nowruz is celebrated and observed by Iranian peoples and the related cultural continent and has spread in many other parts of the world, including parts of Central Asia, Caucasus, South Asia, Northwestern China, the Crimea and some groups in the Balkans.

Nowruz marks the first day of spring and the beginning of the year in Iranian calendar. It is celebrated on the day of the astronomical vernal equinox, which usually occurs on March 21 or the previous/following day depending on where it is observed. As well as being a Zoroastrian holiday and having significance amongst the Zoroastrian ancestors of modern Iranians, the same time is celebrated in parts of the South Asian sub-continent as the new year. The moment the Sun crosses the celestial equator and equalizes night and day is calculated exactly every year and Iranian families gather together to observe the rituals.