> For the complete documentation index, see [llms.txt](https://docs.whalesync.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.whalesync.com/features/additional-features/sync-frequency.md).
# Sync frequency
Sync frequency controls how often Whalesync scans a connection for changes. You set it per connection, in your sync's **Settings** tab under **Connections**.
Each connection defaults to the fastest frequency supported. You can slow a connection down, which reduces how often Whalesync calls that app's API. This is useful when an app has strict API limits, or when you want to control when changes propagate.
Each connection shows its current sync frequency
### Real-time updates (webhooks)
When an app supports webhooks, it sends Whalesync a notification the moment data changes. Whalesync processes those changes as they arrive, so there's no scan interval to set.
While real-time updates are on, the **Sync frequency** option is hidden for that connection.
Turn **Real-time updates (webhooks)** off if you'd rather scan on a schedule. The sync frequency option appears once webhooks are disabled.
With webhooks off, Whalesync scans on the schedule you choose
### Choosing a frequency
Two kinds of schedule are available:
* **Interval** — scan on a fixed cadence, such as every 12 hours.
* **Custom (cron)** — scan on a cron schedule, such as midnight every day. Choose **Custom…** and enter a cron expression.
Cron expressions run in your account's timezone. Whalesync shows a summary of the expression you entered so you can confirm it's what you meant.
Custom cron schedules run in your account's timezone
You can set a connection to scan less often than the default, but not more often.