To see which services are considered Specific Day services in Shiptheory see this support article.
Specifying the date with ship_date
If you use the Shiptheory API, then you can specify a date in the ship_date field. If this is set on a Shipment then this is used as the value for due date when booking with Specific Day services via Pall-Ex. You read more about ship_date and the Shiptheory API here.
Specifying the date using the Delivery Date Auto-Select
If you don't use the API, you can use the Delivery Date Auto-Select advanced setting. Enable this setting by entering a value in the number input. Valid values are numbers from 0 to 7. If ship_date is not present on a shipment and the setting is enabled, then Shiptheory will set the due date of the shipment as n days from the day of booking, where n is the value saved in the setting.
In addition to this setting, you can also enable and disable setting due dates on weekends. If a due date falls on a weekend and the day is not enabled, then the next available day will be used. For example, if the due date falls on a Saturday Shiptheory will check to see if Sunday is enabled. If it is, then the due date will be set to Sunday. If not, then the due date will be set to Monday.
