Samvatsar or Samvat in short. A measurement of year according to the rounds of Jupiter planet around the Sun. There are many kinds of year are in use on this Earth, such as Gregorian calendar, Julian calendar. In India there are Vikram Samvat and Shak Samvat for Hindu, Hijari year for Muslim. The most commonly used and known throughout the world is the Gregorian year measured according to the Sun.

Samvatsar is the Sanskrit term for one year. In Hindu tradition there are are 60 Samvatsar (see  their names in Measurement Time-1).

Kaal Maan and Kaal Chakra have been well defined bringing out concepts of Ayan (2 Ayan), Ritu (6 Ritu - 2 months each), Maas (2 Paksh each), Abdhi Vatsar, Yug (4 Yug) and so on so forth. We also have Samvatsar according to various approaches like Chandra Maan, Saur Maan, Baarhamanasa. It is the last one related to Brihaspati/ Guru is according Brihaspati.

The duration of the year according to the Saur Maan is different from Chandra Maan. If one is 30, the other one is based on Tithi, Nakshatra goes to 360+ and matches with rotation of the Moon and elliptical. Astronomical concepts as Khagol seems to have influence on Ganit (Arithmetic)  and Jyotish (astrology) as we know.

These 6o Samvatsar with names commencing from Prabhav and all these definitions, calculations along with V-Ghadiyaa, Ghadiya, Horaa, Dinamaan are dealt in standard Panchaang as information, likewise we have Maas in different ways and names - Chaitra as well as Mesh ending with Phaalgun. The commencement of year depend and gets adopted based on the regional approaches also. The classifications and names have been given and adopted in every lucid way to avoid any mix up and they can also be joined with Gregorian or western calendar. Nandan named Samvatsar commences with Chaitra Shukla Prathamaa whereas solar year started with Mesh Sankraman (Sankraanti) on April 14th.

Names of Some Samvatsar

There are many Samvatsar in use in he world. Here are given the names of some Samvatsar or years in use by people of the world - See also Vaidik Calendar, Baarhaspatya Measurement of Time

Gregorian Calendar
Used by whole world for the ease of calculating all dates and time throughout the world. All holidays are observed by this calendar.

Hijaree
Used by Muslims. Started by Muhammad Saahab

Julian Calendar
Used by Ethiopians. Of 13 months - 12 months of 30 fays with a short 13th month of 5 or 6 days. Their new year is on 6th September.

Kaalchooree

Kaarttikaadi Samvat
Kaarttikaadi Samvat was started in Somnaath temple - another Shiv temple (or Jyotirling) - Vikram Samvat was startedx in Pashupatinaath temple, Nepaal in 57 BC. This was for shipping purpose as no cyclones come after Kaarttik month.

Kollam Era
Kollam era Malayaalam calendar followed in Kerala, except in Maalaabaar area. It was started by a Cheraa King Raajshekhar Varmaa with the Tarissapalli copper plates of 825 AD to Assyrian Monk Mar Abo which introduced Syrian liturgy among Vaishnavite Nambudiree Christians of Cheraa Kingdom (present south and central Kerala). it is a sidereal solar calendar which consists of 12 months and each month is named after the constellation rising in the orbit of the Earth. Medom is the first month according to the astronomical calendar; it is identical with Chaitra month of the Shak Varsh (era). The first of these months are supposed to mark the Vernal Equinox. Astronomically the calendars need to be corrected to coincide with actual Vernal Equinox which falls on the 21st of March. (Chaitram 1 usually falls on March 20, and Medom 1 falls on April 14).

Laukik Era or Saptarshi Calendar or Yudhishthair Shak
Still in use in Kashmeer.

Nand Shak
Started in 1500

Saptarshi Calendar (Era) or Laukik Era or Yudhishthair Shak
Still in use in Kashmeer. Started in 3076 BC. The 5th of Shraavan Maas fell on a Saturday in the year 87 of any century, except in 4687, and 4487. Shraavan 5th correspondences to Aug 13, 1611 (Gregorian calendar). Saturday Shraavan 5, 4487 corresponding to Jul 25, 1411 (of the Julian calendar)

Shaalivaahan Samvat
Started in 78 AD - by Shaalivaahan - still in use by Hindu. Shaalivaahan was the grandson of Vikramaaditya

Shak Nrip Kaal
When the news of ascension of Lord Krishn reached Hastinaapur Yudhishthir coronated Pareekshit and he along with his brothers and Draupadee left Hastinaapur. 25 years later ie, in 3077 BCE when Saptarshi moved from Maghaa Nakshatra, he and his brothers did the Swargarohana and at that time was the start of the Laukik Era or the Saptarshi calendar, which is still the traditional calendar in Kashmeer. That is also the Yudhisthair Shak. After 2526 yeas from that ie., in 3077 - 2526 = 551 BCE the Shak Nrip Kaal started. Varaah Mihir was born in 551-427 = 124 BCE. One cannot just wish away the Shak Nrip Kaal as it has been mentioned definitely. Cyrus, the Great ascended his throne in 551 BCE as his father died that year and that was the start of the Shak Nrip Kaal.

Shishunaag Shak
Started in 1954 BC - used in Burmese history of Buddhism

Shoodrak Shak
Started in 756 BC - called fictitious as his Federation had wiped Assyrian capital Nineveh in 612 BC.

Shree Harsh Shak
Started in 456 BC - mixed up with Harsh Vardhan of 606 AD