Mercury Mahadasha, Ketu Antardasha (Budh–Ketu)

The Ketu antardasha is the second of the nine sub-periods inside the Mercury mahadasha. 17 × 7 ÷ 120 makes the Mercury–Ketu sub-period 11 months 27 days on the classical year of twelve thirty-day months, which is how the texts state it, or 362 days on the solar year of 365.2425 days that the dasha calculator uses.

Ketu’s turn in the Mercury mahadasha comes only after Mercury has run, which takes 2 years 4 months 27 days. When the Mercury–Ketu sub-period gives way to Mercury–Venus, 13 years 7 months 6 days of the Mercury mahadasha remains.

Ketu’s 7 years make every Ketu antardasha 7/120 of the mahadasha containing it, so inside Mercury’s 17 years the Mercury–Ketu sub-period is the seventh-longest of the nine, level with Mercury–Mars, because Mars and Ketu each run 7 years as mahadashas.

The Nine Pratyantardashas of Mercury–Ketu

A pratyantardasha of Mercury–Ketu is 17 × 7 × its own lord’s years ÷ 14,400, and the nine run in cycle order starting from Ketu. Venus’s is the longest inside Mercury–Ketu at 60 days and the Sun’s the shortest at 18 days, on the classical year and rounded to the day.

How Mercury and Ketu Stand to Each Other

Ketu’s row in the friendship lists counts Mercury neutral. Mercury’s row names no node, so the other direction of the Mercury–Ketu relationship has no entry, and this page does not supply one. The nodes have no row in the seven-graha table that kundli matching uses; the node’s own entry is the one printed on its planet page.

Ketu owns no sign in the standard scheme, so the Mercury–Ketu sub-period has no fixed distance between lordships. What stands in for it is the node’s dispositor — the lord of the sign Ketu occupies at birth — which differs from chart to chart.

The Same Pair the Other Way Round: Ketu–Mercury

17 × 7 equals 7 × 17, so the Mercury antardasha of the Ketu mahadasha is exactly as long as Mercury–Ketu: 11 months 27 days. Nothing else about Ketu–Mercury matches. It is the ninth sub-period of Ketu’s 7 years rather than the second of Mercury’s 17; it opens after 6 years 3 days of the Ketu mahadasha, against 2 years 4 months 27 days here; and its pratyantars start from Mercury instead of Ketu.

What the Texts Assign to Mercury and Ketu

The karaka list the tables give Mercury, the mahadasha lord, is speech, writing, trade, accounts, mathematics, maternal uncles and students; for Ketu, the lord of the Mercury–Ketu sub-period, it is moksha, past-life skill, renunciation, occult knowledge and flags and banners. Parashari practice reads the sub-period through the houses each of the two owns and occupies in the birth chart (for Ketu, which owns none, the house it occupies and the lord of its sign), and through where Ketu stands counted from Mercury there. None of that is a forecast, and this page makes none: without a chart, Mercury–Ketu is a length and a position, and the 11 months 27 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–Ketu sub-period is still ahead depends on how far the Moon had gone into the nakshatra. For a birth in Ashwini, Magha or Mula, the Ketu mahadasha comes first, and the Mercury mahadasha is the ninth 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 केतु अंतर्दशा.