# Choose Store time

Pick the simplest clock that matches who should control modeled time.

## Use this when

Use this when starting a [run](/help/definitions.html#definition-run) that needs modeled events over time and you must choose its [store clock](/help/definitions.html#definition-store-clock).

## Before you start

Decide whether an operator, Meguro, or your code owns each time advance. This beginner choice is separate from runner grants, temporal requirement JSON, immutable revisions, and Exam eligibility.

## Steps

| Mode | Control | Use it when |
| --- | --- | --- |
| Manual | An operator advances Store time | You want to inspect each boundary before moving on |
| Automatic | Meguro advances after the first agent call | The agent should run through a bounded scenario without operator steps |
| Code controlled | Your runner copies the server-owned practiceRun.advanceCursor unchanged | Automation must choose exact checkpoints deterministically |

## Success looks like

The active run displays its chosen clock, current modeled day, and next allowed action.

## If it fails

If an advance is rejected, refresh the run state and copy its fresh `practiceRun.advanceCursor` object unchanged. For code-controlled runs, create a fresh one-time runner authorization after time advances; it is shown once, hashed at rest, expiring, revocable, and command-bound.

## Next action

Exercise [one representative bounded write](/help/bounded-write.html#bounded-write). In Meguro, [select the store](https://app.meguro.io/#stores) and continue from its Overview or Runs tab.