An incredibly rare and powerful chronomancy spell that allows the creation of a very short-lived portal backwards through time.
Items that were anachronisms in the destination time are removed, only restored to existence on the bearer's return to his or her own time. Pages from spellbooks or scrolls that referred to spells not yet in existence become blank, only being restored if the bearer travels forward in time again.
The caster can decide upon the destination time and culture, and this can potentially create the other end of the portal at any rough location the caster chooses.
The spell causes those traveling through the portal to age by one year, but their stay in the alternate time cannot last more than thirty days after the portal's creation. Once the time limit has been reached, the time travelers will be forcefully teleported back to their time. The portal will always take the time travelers to the first day of the destination year, and will always return them on the last day of the original year.
Beings cannot exist in two places at once on the timeline, so it is impossible to travel to the same destination time twice, and an attempt to do so will cause the spell to fail catastrophically.
In order to travel to destination time, one must have a detailed knowledge and understanding of that time.
* - (scales of three dragons of different alignments, dust from a dead time elemental, some soil or stones from the destination time)