Jump day
A jump day (English jumper stay ) is part of the standing property of a sailing ship. It serves as part of the rigging to stiffen a mast.
The jump tag is usually available in two versions: as a single or double stay on the leading edge and in the upper part of the mizzen mast or the main mast (e.g. double jump tag on a folk boat ).
By means of three-quarter rigging, the forestay that fixes the main mast towards the bow (forward) grips the mast at three quarters of the mast height and not in the mast top . The jump tag stabilizes the last quarter up to the mast top so that the upper part of the mast can be trimmed (= adjusted) correctly. These explanations essentially also apply to the (rear) mizzen mast, which does not have a forestay, since otherwise the mainsail with the boom would not be freely movable and trimmable.
The jump tag spreads the jump tag with a spreader and thus increases the stiffening effect on the mast.