The year 1999 has an Adhika Mas or additional month between May 16 to June 14. The Hindu calendar is based on the cycles of the Moon and the months are
based on lunar months which vary from 27 to 29 solar days. The lunar year of
twelve months consists of 354 solar days. However a solar year consists of 365
days which is the basis of civil calendars. There is a difference of 11 days between
the lunar year and the solar year. Due to this difference the two calendars move
out of synchronization and we notice that Holi is celebrated earlier and earlier in Spring every
year as well as Diwali in the Fall. However in about two and a half years a
difference of 29 days accumulates between the two calendars. Hence every two
and half years an additional month or adhika masa (thirteenth month) is added to
the Hindu calendar to bring it back in synchronization with the solar calendar. The
astronomical rule for adding the Adhika Mas is that it occurs in a lunar month when
no Solar Samkranti or transit occurs. Dwisankranti Masah Kchaykhyah Kadachita or
a lunar month that falls between two Sankrantis is additional or expunged.
Since this is a floating month, no celebrations are held in this month. However this
month is also called Purusottam Mas and it is dedicated to the Uttam Purush or
Lord Krishna himself. The Maha mantra for this month is:
The one who held the Govardhan mountain aloft and who also tended the cows, I
sing his praise. Govinda who is celebrated in the festivals of Gokul and who is
loved by all Gopis.
In this month one is supposed to live simply, chant the Maha mantra, worship idols
of Sri Krishna clad in an yellow robe accompanied by Sri Radhika, sing Kirtan in the
streets, protect cows and help widows or women in distress.
Please consult the Hindu Almamnac created for you on the following web site for all your information needs on the various festivals, weddings, hora, namkaran, shraddha etc. The site is free.