Navratri is beginning from tomorrow i.e 18th March 2018 to 25th March 2018. This is the first navratra of Chaitra month. (Chaitra month begins with the new moon in March/April). It is said that whenever Gods were in trouble, Goddesses came to help them and protect them. Since time immoral, it is established that Goddess powers are limitless and are in abundance. All Goddess are symbolic to divine force and their powers are used against evils and negative forces and for peace. All Goddesses – Durga, Laxmi, Kali , Saraswati are worshipped with reverence.
Now coming to your question, one Navratri is celebrated in summer and another in winter. This is also a time of harvesting and seasonal changes. Goddess Durga embodies the entire nature in herself and by worshipping her we protect us through nature. The change in weather caused change everything around us and by worshipping to Goddess, we acknowledge and welcome the change.
Also note that during both Navratris, day and night are approximately equal number of hours, the weather is perfect, neither too hot, nor too cold, just perfect.
Twice a year have all spiritual, mythological and scientific reason.
