The period for acquisition of right of easement to use of light or air, way or other easement by prescription under Section 25 (1) of Limitation Act is:

Easement Act: Section 25.   Acquisition of easements by prescription: (1) Where the access and use of light or air to and for any building have been peaceably enjoyed therewith as an easement, and as of right, without interruption, and for twenty years, and where any way or watercourse or the use of any water or any other easement (whether affirmative or negative) has been peaceably and openly enjoyed by any person claiming title thereto as an easement and as of right without interruption and for twenty years, the right to such access and use of light or air, way, watercourse, use of water, or other easement shall be absolute and indefeasible.