In Vedic astrology, the Gandantas (from Sanskrit "ganda" — knot, and "anta" — end) are six special zodiac zones located at the junctions of water and fire signs: Pisces → Aries, Cancer → Leo, Scorpio → Sagittarius. Each zone spans the last 3°20' of a water sign (the end of the nakshatra Revati, Ashlesha or Jyeshtha) and the first 3°20' of a fire sign (the beginning of Ashwini, Magha or Mula) — a total of 6°40' of "knot" longitude at each junction.

According to the classical texts, a gandanta is the point where one great cycle of experience ends while the next has barely begun. Water is emotion, the past, dissolution; fire is beginning, action, new initiative. Between them there is no smooth transition: a transiting planet seems to "drown" in one element and then "ignite" in the other. When a planet passes through a gandanta, its natural themes — power, emotion, action, thought, faith, relationships, discipline — take on the colour of a transitional state: overall sensitivity rises, familiar supports weaken, subtle processes come to the surface.

The three gandantas have distinct traditional names: Revati–Ashwini (Pisces–Aries) — Sva-gandanta, the knot of individuality and personal beginning; Ashlesha–Magha (Cancer–Leo) — Matri-gandanta, the knot of emotions, roots and the mother line; Jyeshtha–Mula (Scorpio–Sagittarius) — Pitri-gandanta, the knot of authority, faith and spiritual direction. Each planet's passage through a given gandanta is coloured by two factors at once — the nature of the planet itself and the theme of the very knot it has entered.

The gandanta effect is most pronounced during transits of slow planets — Jupiter, Saturn, Rahu and Ketu: they spend weeks and months in the knot, shaping a long collective background. Transits of fast planets — the Sun, Mercury, Venus, Mars — last several days and act as short activations of the theme. The Moon passes each knot about once every two weeks in a few hours, often marking days with an especially subtle emotional atmosphere.