> For the complete documentation index, see [llms.txt](https://docs.decube.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.decube.io/data-quality/monitor-configuration-settings/custom-scheduling-for-monitors.md).

# Custom Scheduling For Monitors

{% hint style="info" %}
Custom scheduling applies to Scheduled monitors only. On-Demand monitors are triggered manually and do not use a frequency setting.
{% endhint %}

Scan frequency controls how often a Scheduled monitor runs. The frequency you choose also determines how much historical data the ML model collects during training — higher-frequency monitors collect a shorter lookback window; lower-frequency monitors collect a longer one. See the [historical lookback table](/data-quality/anomaly-detection-explained.md#historical-lookback-by-scan-frequency).

***

## Available frequencies

| Frequency      | Additional settings                               |
| -------------- | ------------------------------------------------- |
| Every 1 hour   | Timezone                                          |
| Every 3 hours  | Timezone                                          |
| Every 6 hours  | Timezone                                          |
| Every 12 hours | Timezone                                          |
| Daily          | Timezone, time of day                             |
| Weekly         | Timezone, day of week, time of day                |
| Monthly        | Timezone, day of month (or last day), time of day |

<figure><img src="/files/Go9hNpX2QHuOH4kp92qu" alt=""><figcaption><p>Frequency selector for a Scheduled monitor</p></figcaption></figure>

***

## Daily scheduling

For daily monitors, you configure:

* **Timezone** — the timezone used to interpret the scheduled time
* **Time of day** — the hour at which the monitor runs (24-hour format)

<figure><img src="/files/LxGRxtdxpfUiUgWjmGxL" alt=""><figcaption><p>Daily scheduling options</p></figcaption></figure>

Schedule daily monitors to run after your ETL jobs complete, so the scan reflects the latest data.

***

## Weekly scheduling

For weekly monitors, you configure:

* **Timezone**
* **Day of week** — which day the monitor runs
* **Time of day**

<figure><img src="/files/0TMRHOVVe9NelJCIcwLN" alt=""><figcaption><p>Weekly scheduling options</p></figcaption></figure>

***

## Monthly scheduling

For monthly monitors, you configure:

* **Timezone**
* **Day of month** — a specific date (up to the 28th) or the last day of the month
* **Time of day**

Use the **last day of the month** option when you need to monitor month-end data regardless of whether the month has 28, 30, or 31 days.

<figure><img src="/files/0Olj8UJauZCj5qkI3ffz" alt=""><figcaption><p>Monthly scheduling options</p></figcaption></figure>

***

## Choosing the right frequency

Match the scan frequency to how often your data actually changes:

* If your pipeline loads data hourly, an hourly monitor catches issues within the same cycle.
* If your pipeline runs once daily (for example, a nightly ETL), a daily monitor scheduled shortly after the load completes is sufficient.
* For reference tables or slowly-changing dimensions, weekly or monthly is appropriate.

{% hint style="warning" %}
Changing scan frequency on a monitor that uses Smart Training triggers a retrain and deletes all historical data. See [Retraining Monitors](/data-quality/monitor-configuration-settings/retraining-monitors.md).
{% endhint %}

{% content-ref url="/pages/ywQFsioEFNJ8sKDYoSlw" %}
[Available Monitor Modes](/data-quality/monitor-configuration-settings/available-monitor-modes.md)
{% endcontent-ref %}