Guru (Jupiter) mahadasha for Mithuna (Gemini) Moon sign

In the Vimshottari system a life moves through nine long periods, each ruled by one planet. The planet that rules the period sets the tone of those years: the areas of life that come forward, and the kind of effort that pays.

The Jupiter mahadasha lasts 16 years in full. Most people meet it partway through, so the part they live through can be shorter.

Jupiter stands for wisdom, teachers, children, growth and faith. Its period tends to widen life: learning, guidance, family growth and a stronger sense of meaning.

Counted from Gemini as the first house, Jupiter rules Sagittarius and Pisces, your 7th and 10th houses. During its period the matters of both come forward:

The 7th house is partners, marriage and dealings with other people. Its lord's period tends to bring partnerships forward, in marriage and in business, and to teach through other people.

The 10th house is career, standing and public life. Its lord's period tends to put work and responsibility in front, with chances to rise for those who carry them.

Jupiter counts Mercury, the lord of Gemini, as a natural enemy. Its themes may meet some friction with your temperament, so patience and a steady routine help the period give its best.

Which mahadasha you are in, and when it began, depends on the Moon's nakshatra at the moment you were born, so it is personal to you. Even within the Jupiter mahadasha, where the planet sits in your own chart and the sub-periods inside it shape the years more than your Moon sign alone.