There are two types of Sandglasses, one that functions as per the Tempore Finis spell when turned over, the other that works like the Tempore Saltus spell when powered.
The first type, the Sandglass of Stopped Time, will stop time for the person who turns it over for some fixed number of perceived Combat Turns (determined at creation). The sandglass does not need to remain in the person's possession for the duration of stopped time. (Which is zero. Time has stopped. Pay attention.) When the last grain of sand drops, time resumes. The Sandglass can be carried and moved but cannot be turned over again before the sand runs out.
The second type of Sandglass is recognizable by its lack of sand, making it a sandless sandglass. (Sandlessglass?) (Sandglassless?) (Sharon Gless?). When the Sandglass of Skipped Time is turned over and Powered to beat a 4 (half the base for the spell) the character jumps forward in time an Adventure Turn for each PoS. This number of Turns is based solely on the Success; the character cannot choose how far to jump. If the powering fails, the Sandglass cannot be used again for a Travel Turn per PoF.
[[The third type, the Cursed Sandglass of Stopped Time, looks and acts like a Sandglass of Stopped Time but places the person turning it over in Suspended Animation, per the Vita Dilatio spell, for some fixed number of Travel Turns (determined at creation). The target number to remove the curse using a Cure spell is 9 plus the number of Turns remaining in suspension.]]