Dasha Sandhi: The Nine Mahadasha Joins and Their Sub-Periods

What Dasha Sandhi Refers To (दशा संधि)

Sandhi means a joint or a meeting point. Dasha sandhi is the name jyotishis give to the stretch on either side of the moment one Vimshottari mahadasha ends and the next begins, such as the Ketu-to-Venus or Rahu-to-Jupiter change. The site’s tables give the sandhi no fixed width, and practitioners who use the term do not agree on one: some speak of the closing and opening sub-periods, others of a few months either side. This page does not choose between them. It sets out what is fixed at every join, which is the order and length of the sub-periods that meet there.

The Vimshottari cycle has nine lords, Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury, so it has nine joins, and a life meets them in that order starting from whichever lord was running at birth. When the first join comes depends on the balance of dasha at birth; after it the joins are a full mahadasha apart.

Every Mahadasha Closes on the Lord Before It

Inside a mahadasha the nine antardashas run in cycle order beginning with the mahadasha lord’s own. The last of the nine is therefore the lord that comes just before it in the cycle, which is also the lord of the mahadasha that came before. Rahu’s mahadasha, which follows Mars’s, closes on Rahu–Mars; Jupiter’s, which follows Rahu’s, closes on Jupiter–Rahu. The same rule repeats one level down, so the last pratyantardasha of a closing antardasha is two steps back in the cycle.

At every join the pattern is the same. In the last months of a mahadasha its lord holds only the top level, with its predecessor at the antardasha level and the lord before that at the pratyantardasha level. In the first months of the next mahadasha the new lord holds all three.

The Nine Joins in One Table

Lengths are in years of twelve 30-day months, the reckoning the texts use. A calculator on the 365.2425-day solar year prints each one about 1.5% longer on the calendar.

Some Joins Are Short and Some Are Long

Measured as the closing antardasha plus the opening one, the narrowest join is Moon to Mars: Moon–Sun and Mars–Mars together run 10.9 months. The widest is Jupiter to Saturn, where Jupiter–Rahu and Saturn–Saturn together run 64.9 months, because Jupiter–Rahu pairs sixteen years with eighteen and Saturn–Saturn nineteen with nineteen. The shortest opening of all is the Sun’s: the Sun–Sun antardasha lasts 3 months 18 days, and its first pratyantardasha 5 days.

The two sides are rarely balanced. At five joins, from Venus, the Sun, the Moon, Saturn and Mercury, the closing antardasha outlasts the opening one; at the other four the new lord’s own sub-period is the longer. A width taken as a fixed number of months either side therefore covers a different share of the sub-periods at each join.

Ketu to Venus

The Ketu mahadasha ends inside Ketu–Mercury, 11 months 27 days long, whose last pratyantardasha is Saturn’s, 1 month 27 days. The Venus mahadasha opens with Venus–Venus, 3 years 4 months, itself opening on a Venus–Venus–Venus pratyantardasha of 6 months 20 days, and then passes to Venus–Sun. Taken together, the two antardashas either side of this join run 51.9 months.

A seven-year mahadasha meets the longest one in the cycle, twenty years, and the opening Venus–Venus antardasha is 3.4 times as long as the closing Ketu–Mercury one. Only the Mars-to-Rahu join is more uneven, at 4.6 times.

Rahu to Jupiter

The Rahu mahadasha ends inside Rahu–Mars, 1 year 18 days long, whose last pratyantardasha is the Moon’s, 1 month 2 days. The Jupiter mahadasha opens with Jupiter–Jupiter, 2 years 1 month 18 days, itself opening on a Jupiter–Jupiter–Jupiter pratyantardasha of 3 months 12 days, and then passes to Jupiter–Saturn. Taken together, the two antardashas either side of this join run 38.2 months.

Rahu’s mahadasha closing on Rahu–Mars means the last antardasha before Jupiter is the one that pairs the node with the lord whose mahadasha preceded Rahu’s. This is one of four joins in the cycle that involve a node: Ketu to Venus, Mars to Rahu, Rahu to Jupiter and Mercury to Ketu.

Saturn to Mercury

The Saturn mahadasha ends inside Saturn–Jupiter, 2 years 6 months 12 days long, whose last pratyantardasha is Rahu’s, 4 months 17 days. The Mercury mahadasha opens with Mercury–Mercury, 2 years 4 months 27 days, itself opening on a Mercury–Mercury–Mercury pratyantardasha of 4 months 3 days, and then passes to Mercury–Ketu. Taken together, the two antardashas either side of this join run 59.3 months.

Here both sides are long. Saturn–Jupiter combines nineteen years with sixteen and Mercury–Mercury seventeen with seventeen, so neither the closing nor the opening antardasha is under two years.

Mercury to Ketu, and the Same Join at Birth

The Mercury mahadasha ends inside Mercury–Saturn, 2 years 8 months 9 days long, whose last pratyantardasha is Jupiter’s, 4 months 9 days. The Ketu mahadasha opens with Ketu–Ketu, 4 months 27 days, itself opening on a Ketu–Ketu–Ketu pratyantardasha of 9 days, and then passes to Ketu–Venus. Taken together, the two antardashas either side of this join run 37.2 months.

Because the dasha lords also rule the nakshatras in the same cycle, this one join also appears in the sky. The Moon crosses it every time it passes from a Mercury nakshatra into a Ketu one, and that happens at three places: Ashlesha to Magha, Jyeshtha to Mula and Revati to Ashwini. Those six nakshatras are the ones counted as gandmool. A birth with the Moon at the end of Ashlesha opens on the last days of a Mercury mahadasha; a birth an hour or two later, in Magha, opens on almost all seven years of Ketu’s.

The Other Five Joins

Finding Your Own Joins

The table holds the shape of every join; the dates need a birth. The dasha calculator prints the date each mahadasha begins, and each of those dates is a join. The how to read your dasha guide walks through a complete timeline, and the antardasha table lists all 81 sub-periods with their lengths. For the system as a whole, see Vimshottari dasha explained.

What This Page Does Not Say

Nothing here says what a join brings, whether any join is harder than another, or what to do or avoid near one. In Parashari practice the periods on either side are read through the houses their lords rule and occupy in the birth chart, and a table of lengths holds none of that. The page gives no width for the sandhi, no remedy for it, and no age at which any join arrives, since that depends on the balance at birth. In Hindi: दशा संधि: महादशाओं के नौ जोड़ और उनकी उप-अवधियाँ.