Time Portal

You draw a 3 foot wide and 7 foot tall doorway on a wall or other vertical surface inscribed with sigils that link your location in time and space to a permanent time portal of your choice whose sigil sequence you have learned. In a few obscure or hidden places in forgotten temples or tombs at various points in time there have existed (or will exist) permanent time portals inscribed somewhere within their confines. Upon casting the spell, a shimmering portal opens within the doorway you drew and remains open until the end of your next turn. Any creature that enters the portal instantly steps out of the destination doorway into the nearest unoccupied space.Time advances at the same speed at both ends of the portal, so when you return, the amount of time that will have passed here will equal to the amount of time you spent on the other side. A sigil sequence is a string of magical runes arranged in a particular pattern. Each permanent time portal has a unique sigil sequence. When you first gain the ability to cast this spell, you learn two sigil sequences to destinations determined by the Dungeon Master. One of these will exist at your current time, but in some hidden location and the other will exist in either the future or the past and at a different location. You can learn additional sigil sequences during your adventures. You can commit a new sigil sequence to memory after studying it for a minute. You can create a permanent time portal by casting this spell every day for one year in one location. You need not use the doorway to travel to the other time when you cast the spell in this way.