# Units: Clock

> Up, down, match and wall-clock timing.

Glider documentation · Logic · Web page: https://cgglider.com/docs/units/clock/

Sections of this page: [Overview](https://cgglider.com/docs/units.md) · [Clock](https://cgglider.com/docs/units/clock.md) · [Counter](https://cgglider.com/docs/units/counter.md) · [Ticker](https://cgglider.com/docs/units/ticker.md) · [Formatter](https://cgglider.com/docs/units/formatter.md) · [Watch rule](https://cgglider.com/docs/units/watch-rule.md) · [Data feed](https://cgglider.com/docs/units/poller.md) · [Runtime & gating](https://cgglider.com/docs/units/runtime.md) · [Commands & API](https://cgglider.com/docs/units/commands.md)

| Field | Meaning |
| --- | --- |
| Mode | up (count up), down (count down), match (a period-aware match clock), wall (time of day). |
| Target | The store path the formatted time is written to. |
| Format | mm:ss · h:mm:ss · ss · mm:ss.t · HH:mm · h:mm a |
| Duration | Required for a countdown. |
| Period minutes | Match clocks: the length of a period. |
| Added seconds | Stoppage time added to a match clock. |
| Timezone | Wall clocks only. |
| Zero path | A path written when the clock reaches zero. |
| Running | Start or stop from the unit header. Reset remains beside the current clock value. |

## Actions

- start · pause · resume · stop · toggle · reset
- add — add time to a running clock
- set — jump to a specific value

> **Note:** A countdown without a duration is rejected: “A countdown needs a duration.” The editor validates on every edit and refuses the patch rather than storing a broken unit.

![A match clock unit.](https://cgglider.com/docs-shots/unit-clock.png)