There are several different options to control how often a sync will be started.

Aside from the settings for your sync, other factors will impact when and how often a sync will be started, such as your plan, the remote server's maximum allowed connections, and the system's maximum number of running syncs.

Any particular sync will only run 1 sync job at a time, regardless of its trigger settings. If a sync run is already in progress when the next sync run would start, the second sync run will be skipped.

Automatic Interval (in minutes)

The Automatic Interval (in minutes) option is used for starting a sync repeatedly, such as every 45 minutes or every 240 minutes.

The number you enter determines how many minutes apart each job will be started. Your plan will limit how small this number may be.

Schedule Interval

Choose a pre-defined Schedule Interval. This is often helpful for a sync that does not need to run every day. Syncs will start after midnight UTC on the appropriate day.

Recurring Day

For syncs that should run once per month, but not on the first or last day of the month, choose Recurring Day and supply the Day of the month. Syncs will start after midnight UTC on the appropriate day.

For example, if you need to push items to a remote server by the 14th of the month, you could schedule your sync to be triggered on the 13th.

Custom Schedule

The Custom Schedule provides a highly configurable set of options for when the sync will be started, including the hour of the day when syncs will run.

You can choose to restrict the sync to only specific Days of the week and enter one or more Time of day hours to start the sync, along with the desired Time zone.

For example, you could configure a daily sync (by selecting each day of the week) that runs after the close of business (such as 5pm within your timezone).

External Trigger

The External Trigger option will allow your sync to be started by a Run Sync Automation.

When this option is chosen, the sync can only be triggered "as needed" rather than being triggered on a schedule.

This option is intended to be used in conjunction with an Automation. Create an Automation configured with the Run sync option to trigger this sync.

Combining a sync with an Automation this way allows you to trigger the sync via an incoming webhook by using the Incoming webhook trigger for the Automation.