The Hindu metrics of time can be summarized as below.

Hindu Kaala Vyavahara (Metrics of Time)

Table of contents
1 Sidereal metrics
2 Lunar metrics
3 Tropical metrics

Sidereal metrics

Small units of time used in the vedas

Lunar metrics

  • a Tithi (also spelled thithi) or lunar day is defined as the time it takes for the longitudinal angle between the moon and the sun to increase by 12. Tithis begin at varying times of day and vary in duration from approximately 19 to approximately 26 hours.
  • a paksa or lunar fortnight consists of 15 Tithis
  • a masa or lunar month (approximately 29.5 days) is divided into 2 paksas: the one between new moon and full moon is called gaura (bright); the one between full moon and new moon krishna (dark)
  • 2 lunar months are 1 Ruthu
  • 3 Ruthus are 1 Aayanam
  • 2 Aayanas are 1 year

Tropical metrics

Years are grouped into yugas (ages):

The Four Yugas
1,728,000 solar yearsSatya Yuga
1,296,000 solar years Treta Yuga
864,000 solar yearsDwapar Yuga
432,000 solar yearsKali Yuga

  • One cycle of the above four yugas is one \mahayuga (4.32 million solar years)
  • A manvantara consists of 71 mahayugas (306,720,000 solar years)
  • After each manvantara follows one Sandhi Kala of the same duration as a Krita Yuga (1,728,000 solar years). (It is said that during a Sandhi Kala, the entire earth is submerged in water.)
  • A kalpa consists of a period of 1,728,000 solar years called Adi Sandhi, followed by 14 manvantaras and Sandhi Kalas for a total of 1000 mahayugas or 4,320,000,000 (4.32 billion) solar years.
  • Two kalpas constitue a day and night of Brahma; the life cycle of Brahma is one hundred years of Brahma, or 311 trillion years.

The current Kali Yuga (Iron Age) began at midnight 17/18 February 3102 B.C. in the proleptic Julian calendar.

It has been suggested that we are entering a short period of relative light within this otherwise dark time for humanity and the higher beings. PLEASE CORRECT THIS IF NECESSARY.