Vedic and Puranic units of time span from the truti (microsecond) to the mahamantavara (311.04 trillion years). Hindu theology considers the creation and destruction of the universe a cyclic process.
Contents 
Old Indian measures are presently used primarily for religious purposes in Hinduism and Jainism. They also are employed in the teachings of Surat Shabda Yoga.
The Hindu cosmological time cycles are described in verses 11–23 of Chapter 1, Surya Siddhanta:^{[1]}
(Verse 11). That which begins with respirations (prāna) is called real; that which begins with atoms (truti) is unreal. Six respirations make a vinādi, sixty of these a nādi.
(12). And sixty nādis make a sidereal day and night. Of thirty of these sidereal days is composed a month; a civil month (sāvana) consists of as many sunrises.
(13). A lunar month, of as many lunar days (tithi); a solar (sāura) month is determined by the entrance of the sun into a sign of the zodiac; twelve months make a year. This is called a day of the devas or demigods.
(14). The day and night of the devas and of the asuras are mutually opposed to one another. Six times sixty of them are a year of the devas, and likewise of the asuras.
(15). Twelve thousand of these divine years are denominated a chaturyuga (chatur=Four; yuga=Ages); of ten thousand times four hundred and thirtytwo solar years.
(16) The difference of the krtayuga and the other yugas, as measured by the difference in the number of the feet of Dharma in each, is as follows :
(17). The tenth part of a chaturyuga, multiplied successively by four, three, two, and one, gives the length of the krta and the other yugas: the sixth part of each belongs to its dawn and twilight.
(18). One and seventy chaturyugas make a (manvantara (Patriarchate of one Manu); at its end is a twilight which has the number of years of a krtayuga, and which is a pralaya (catastrophic end of creation).
(19). In a kalpa (æon) are reckoned fourteen such Manus with their respective twilights; at the commencement of the kalpa is a fifteenth dawn, having the length of a krtayuga.
(20). The kalpa, thus composed of a thousand chaturyugas, and which brings about the destruction of all that exists, is a day of Brahma; his night is of the same length.
(21). His extreme age is a hundred, according to this valuation of a day and a night. The half of his life is past; of the remainder, this is the first kalpa.
(22). And of this kalpa, six Manus are past, with their respective twilights; and of the Patriarch Manu son of Vivasvant, twentyseven chaturyugas are past;
(23). Of the present, the twentyeighth chaturyuga, the krtayuga is past; from this point,reckoning up the time, one should compute together the whole number.
The Hindu metrics of time (Kālm Vyavahara) can be summarized as below.
An alternate system described in the Vishnu Purana Time measurement section of the Vishnu Purana Book I Chapter III is as follows:
The Vishnu Purana Time measurement section of the Vishnu Purana Book I Chapter III explains the above as follows:
(Two kalpas constitute a day and night of Brahma)
One day of Brahma is divided into 10,000 parts called charanas. The charanas are divided as follows:
4 charanas (1,728,000 solar years)  Satya Yuga 
3 charanas(1,296,000 solar years)  Treta Yuga 
2 charanas(864,000 solar years)  Dwapar Yuga 
1 charanas(432,000 solar years)  Kali Yuga 
The cycle repeats itself so altogether there are 1,000 cycles of mahayugas in one day of Brahma.
Currently, 50 years of Brahma have elapsed and we are in the first Day of the 51st year. This Brahma's day, Kalpa, is named as ShvetaVaraha Kalpa. Within this Day, six Manvantaras have already elapsed and we are in the seventh Manavatara, named as  Vaivasvatha Manvantara. Within the Vaivasvatha Manavantara, 27 Mahayugas (4 Yugas together is a Mahayuga), and the Krita, Treta and Dwapara Yugas of the 28th Mahayuga have elapsed. We are in the Kaliyuga of the 28th Mahayuga. This Kaliyuga began in the year 3102 BC in the proleptic Julian Calendar. Since 50 years of Brahma have already elapsed, we are in the second Parardha, also called as Dvithiya Parardha.
The time elapsed since the current Brahma has taken over the task of creation can be calculated as
432000 x 10 x 1000 x 2 = 8.64 Billion Years (2 Kalpa(day and night) )
[8] 8.64 x 10^{9} x 30 x 12 = 3.1104 Trillion Years (1 year of Brahma)
3.1104 x 10^{12} x 50 = 155.52 Trillion Years (50 years of Brahma)
(6 x 71 x 4320000 ) + 7 x 1.728 x 10^{6} = 1.973 billion years elapsed in first six Manvataras, and Sandhi Kalas in the current Kalpa
27 x 4320000 = 116.640000 million years elapsed in first 27 Mahayugas of the current Manvantara
1.728 x 10^{6} + 1.296 x 10^{6} + 864000 = 3.888 million years elapsed in current Mahayuga
3102 + 2010 = 5112 years elapsed in current Kaliyuga.
So the total time elapsed since current Brahma is
155.52 x 10^{12} + 1.973x10^{9} + 0.00012053302 = 155.52 Trillion Years
The current Kali Yuga began at midnight 17 February / 18 February in 3102 BC in the proleptic Julian calendar.

