Rahu Mahadasha, Ketu Antardasha (Rahu–Ketu)

The Ketu antardasha is the fifth of the nine sub-periods inside the Rahu mahadasha. 18 × 7 ÷ 120 makes the Rahu–Ketu sub-period 1 year 18 days on the classical year of twelve thirty-day months, which is how the texts state it, or 384 days on the solar year of 365.2425 days that the dasha calculator uses.

Ketu’s turn in the Rahu mahadasha comes only after Rahu, Jupiter, Saturn and Mercury have run, which takes 10 years 6 months. When the Rahu–Ketu sub-period gives way to Rahu–Venus, 6 years 5 months 12 days of the Rahu mahadasha remains.

Ketu’s 7 years make every Ketu antardasha 7/120 of the mahadasha containing it, so inside Rahu’s 18 years the Rahu–Ketu sub-period is the seventh-longest of the nine, level with Rahu–Mars, because Mars and Ketu each run 7 years as mahadashas.

The Nine Pratyantardashas of Rahu–Ketu

A pratyantardasha of Rahu–Ketu is 18 × 7 × its own lord’s years ÷ 14,400, and the nine run in cycle order starting from Ketu. Venus’s is the longest inside Rahu–Ketu at 63 days and the Sun’s the shortest at 19 days, on the classical year and rounded to the day.

How Rahu and Ketu Stand to Each Other

Neither node’s row in the friendship lists names the other, so the Rahu–Ketu pair has no entry in either direction, and this page does not supply one. They are the two ends of a single axis rather than two grahas with a view of each other.

Neither Rahu nor Ketu owns a sign in the standard scheme, so the Rahu–Ketu sub-period joins no lordships at all; each node is read through the lord of the sign it occupies at birth.

The Same Pair the Other Way Round: Ketu–Rahu

18 × 7 equals 7 × 18, so the Rahu antardasha of the Ketu mahadasha is exactly as long as Rahu–Ketu: 1 year 18 days. Nothing else about Ketu–Rahu matches. It is the sixth sub-period of Ketu’s 7 years rather than the fifth of Rahu’s 18; it opens after 2 years 11 months of the Ketu mahadasha, against 10 years 6 months here; and its pratyantars start from Rahu instead of Ketu.

What the Texts Assign to Rahu and Ketu

The karaka list the tables give Rahu, the mahadasha lord, is foreign lands and foreigners, technology, aviation and politics; for Ketu, the lord of the Rahu–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 the two occupy in the birth chart and the lords of the signs they sit in, since neither owns a sign, and through where Ketu stands counted from Rahu there. None of that is a forecast, and this page makes none: without a chart, Rahu–Ketu is a length and a position, and the 1 year 18 days above is the whole of what can be said about it in general.

A birth with the Moon in Ardra, Swati or Shatabhisha opens life inside the Rahu mahadasha itself, part-way through, and whether the Rahu–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 Rahu mahadasha is the sixth in that sequence.

The Other Sub-Periods of the Rahu Mahadasha

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