Mercury Mahadasha, Jupiter Antardasha (Budh–Guru)

The Jupiter antardasha is the eighth of the nine sub-periods inside the Mercury mahadasha. 17 × 16 ÷ 120 makes the Mercury–Jupiter sub-period 2 years 3 months 6 days on the classical year of twelve thirty-day months, which is how the texts state it, or 828 days on the solar year of 365.2425 days that the dasha calculator uses.

Jupiter’s turn in the Mercury mahadasha comes only after Mercury, Ketu, Venus, the Sun, the Moon, Mars and Rahu have run, which takes 12 years 15 days. When the Mercury–Jupiter sub-period gives way to Mercury–Saturn, 2 years 8 months 9 days of the Mercury mahadasha remains.

Jupiter’s 16 years make every Jupiter antardasha 16/120 of the mahadasha containing it, so inside Mercury’s 17 years the Mercury–Jupiter sub-period is the fifth-longest of the nine.

The Nine Pratyantardashas of Mercury–Jupiter

A pratyantardasha of Mercury–Jupiter is 17 × 16 × its own lord’s years ÷ 14,400, and the nine run in cycle order starting from Jupiter. Venus’s is the longest inside Mercury–Jupiter at 136 days and the Sun’s the shortest at 41 days, on the classical year and rounded to the day.

How Mercury and Jupiter Stand to Each Other

On the natural friendship table, Mercury counts Jupiter neutral while Jupiter counts Mercury an enemy. The table is not symmetric, so the Mercury–Jupiter relationship has to be quoted in both directions, as it is here, rather than as one word.

Counted between the signs they own, Sagittarius is the 7th from Mercury’s Gemini, Pisces is the 10th from Mercury’s Gemini, Sagittarius is the 4th from Mercury’s Virgo and Pisces is the 7th from Mercury’s Virgo. Whatever the ascendant, the houses Mercury rules and the houses Jupiter rules sit at those same distances from each other in the chart, so the Mercury–Jupiter sub-period always joins lordships that far apart.

Mercury is debilitated in Pisces, a sign Jupiter owns. In the Mercury–Jupiter sub-period, then, one lord's dignity is placed on the other’s ground.

The Same Pair the Other Way Round: Jupiter–Mercury

17 × 16 equals 16 × 17, so the Mercury antardasha of the Jupiter mahadasha is exactly as long as Mercury–Jupiter: 2 years 3 months 6 days. Nothing else about Jupiter–Mercury matches. It is the third sub-period of Jupiter’s 16 years rather than the eighth of Mercury’s 17; it opens after 4 years 8 months of the Jupiter mahadasha, against 12 years 15 days here; and its pratyantars start from Mercury instead of Jupiter.

What the Texts Assign to Mercury and Jupiter

The karaka list the tables give Mercury, the mahadasha lord, is speech, writing, trade, accounts, mathematics, maternal uncles and students; for Jupiter, the lord of the Mercury–Jupiter sub-period, it is children, teachers and gurus, higher learning and dharma. Parashari practice reads the sub-period through the houses each of the two owns and occupies in the birth chart, and through where Jupiter stands counted from Mercury there. None of that is a forecast, and this page makes none: without a chart, Mercury–Jupiter is a length and a position, and the 2 years 3 months 6 days above is the whole of what can be said about it in general.

A birth with the Moon in Ashlesha, Jyeshtha or Revati opens life inside the Mercury mahadasha itself, part-way through, and whether the Mercury–Jupiter sub-period is still ahead depends on how far the Moon had gone into the nakshatra. For a birth in Punarvasu, Vishakha or Purva Bhadrapada, the Jupiter mahadasha comes first, and the Mercury mahadasha is the third in that sequence.

The Other Sub-Periods of the Mercury Mahadasha

The full table for the Mercury mahadasha, with where each sub-period opens and closes, is on the Mercury mahadasha page. How the Mercury mahadasha is read as a whole is in our Mercury mahadasha article, and the system itself in Vimshottari dasha explained. This page in Hindi: बुध महादशा में गुरु अंतर्दशा.