Is there a Spacetime Rift timer?

The client says rifts open at random locations at set intervals; it does not publish a fixed schedule. Your time on the other side is limited by Spacetime Rift usage time.

Where does the Spacetime Rift go?

To the enemy faction's land: per the quest text, an Elyos rift leads to Asmodae and an Asmodian rift leads to Elysea.

Can I be attacked through a rift?

Yes — by guards of enemy towns and by enemy players.

Aion 2 Spacetime Rift

A Spacetime Rift is an unstable portal that opens at random locations at set intervals and takes you into the enemy faction's territory — Elyos to Asmodae, Asmodians to Elysea. You can only stay for a limited usage time, enemy town guards and players can attack you, and Spacetime Rift Tickets recharge that time.

In the game's words

Spacetime Rifts are unstable portals that randomly open at certain intervals. They allow you to enter the enemy faction's territory.
You'll only have a limited time to stay in the enemy faction's continent after traveling through the Spacetime Rift.
You may be attacked by guards of enemy towns or enemy players.

Rewards and how it works, per the game

Look for the vortex-shaped icon on the map.
A notification will be displayed server-wide when a Spacetime Rift opens.
You can travel to the enemy faction's continent through the Spacetime Rift and clear Sealed Dungeons, strongholds, etc., there.
You can also engage in PvP against the enemy faction.

Usage time and tickets

Spacetime Rift Ticket: recharges Spacetime Rift usage time by 30 minutes.
Spacetime Rift Duration Ticket: recharges usage time by 10 minutes.
Rift materials (a teardrop-shaped mineral, a volatile substance, a substance that responds to the Netherworld) turn into tickets through Substance Morph.

The Spacetime Rift quests

Each faction has its own chain of regional quests asking you to bring things back from beyond the rift. Elyos get theirs from Mino (Spacetime Rift, Not Quite the Same, Unfamiliar Material, Beautiful Carapace, Pure Plants, Perfect Tool, Trendsetter); Asmodians from Uru (Spacetime Rift, Unknown Species, Unfamiliar Material, Difference Between Here and There, Developing Travel Goods, An Honest Shugo, Proof). The quest text notes the rift appears at random locations at specific times.

Frequently asked

Is there a Spacetime Rift timer?: The client says rifts open at random locations at set intervals; it does not publish a fixed schedule. Your time on the other side is limited by Spacetime Rift usage time.
Where does the Spacetime Rift go?: To the enemy faction's land: per the quest text, an Elyos rift leads to Asmodae and an Asmodian rift leads to Elysea.
Can I be attacked through a rift?: Yes — by guards of enemy towns and by enemy players.

From the AION 2 global client: the in-game Contents Navigator and guide text are quoted as the game shows them, and every number is a value from the client's data tables. Nothing here is taken from another fan site.