The Time Bolts are ammunition for crossbows in Final Fantasy XII. They have a chance of inflicting their target with Doom. Crossbows cannot be equipped without owning some kind of bolts. Owning the Time Bolts means the player can use an unlimited amount, and bolts do not need a license to be equipped alongside a crossbow. The bolts are metallic for the purposes of the magnetize debuff present in the Vinuskar and Ultima boss battles.
Obtain
Original
The Time Bolts are not sold in shops, but sell for 1000 gil. They are found in a treasure in Cerobi Steppe's North Liavell Hills 
. The player can come to Cerobi Steppe early via a chocobo from the Tchita Uplands.
The bolts are made in the bazaar set "Scout's Crossbow" alongside the Penetrator Crossbow. The set costs 17,800 gil and is made by selling four Wyvern Fangs, three Ancient Bones, and nine Holy Crystals. Wyvern Fangs are obtained from Aeronites, flying enemies found in the Lhusu Mines and the Pharos. Ancient Bones are obtained from Dead Bones, such as in the area in the Nabreus Deadlands where Roblon is fought. Holy Crystals are obtained from holy elementals as well as dropped by Babil and stolen from Goliath.
Zodiac
The Time Bolts set is not available in shops but sells for 3500 gil.
The Time Bolts are found in a treasure in Subterra's Umbra - North (70% chance to appear, 20% chance for an item, 50% chance the item treasure is the Time Bolts without the Diamond Armlet equipped), and in Trial Mode Stage 61 with the Diamond Armlet equipped.
The bolts are also commonly stolen from Zalera in Trial Mode Stage 32.
The bolts are still made in the Scout's Crossbow bazaar set for the same items as before, but for a cheaper price: 6,400 gil.
Use
The Time Bolts add 2 points to the crossbow's power and hold the Doom status, which kills the target after the 10-tick timer expires. The status has a 25% flat chance of working on a target who is not immune to Doom, but it will not work on bosses or hunt marks. By using the bolts, the player can save a turn from the Time Battlemage from using Countdown. However, for instant death, the player likely has better methods that do not involve needing to wait out the timer. The player could use the bolts manually and then switch targets after Doom sticks if they want to wait for the timer to bear fruit. Sometimes letting enemies die by the timer is preferable as it does not break the player's chain.
The bolts are only useful to procure in the Zodiac versions if the player is using a Time Battlemage.