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.