Time in Force

TL;DR

Time-in-force on Darknyx is expressed two ways: the order type decides whether an order may rest (limit rests; IOC and FOK do not), and expiry_slot decides how long a resting order lives. Order expiry is measured in Solana slots, not wall-clock time.

The two controls

Control	Field	Effect
May it rest?	order_type	limit rests; ioc and fok execute immediately and never rest.
How long may it rest?	expiry_slot	The slot past which a resting order auto-expires.

Every order carries an expiry_slot, bounded by the market's maximum so a note cannot be locked forever. A resting order is swept when the chain passes that slot.

Available behaviors

GTC: Good-til-Cancelled

A limit order with a far-future expiry_slot. It rests until it fills, you cancel it, or it eventually hits its (distant) expiry. This is the standard resting order.

GTT: Good-til-Time

A limit order with an expiry_slot chosen to match a wall-clock deadline. To place "good for the next ten minutes," read /time for the current slot and project your deadline onto a slot (Solana targets roughly 400 ms per slot). The SDK does this conversion for you:

expiry_slot = current_slot + ceil((deadline_ms - now_ms) / slot_ms)

When the chain passes expiry_slot, the order is swept and an expired event is emitted on the Orders Channel.

IOC: Immediate-or-Cancel

An ioc order. Fills what it can in its arrival batch, cancels the rest. Never rests, so expiry_slot is moot for it.

FOK: Fill-or-Kill

A fok order. Fills its whole size in its arrival batch or is dropped. Never rests and never partially fills.

Summary

TIF	Expressed as	Rests?
GTC	limit + far expiry_slot	Yes, until fill / cancel / expiry
GTT	limit + deadline-derived expiry_slot	Yes, until the deadline slot
IOC	ioc	No
FOK	fok	No

Slots, not timestamps

Because settlement is on Solana, expiry is anchored to the chain's clock, the slot, so it stays consistent with on-chain state. /time gives you both the slot and the wall-clock instant so you can convert between them. See Order Types for how the type controls resting, and Execution Attributes for fill-size constraints.