The dates being shown to customers after an order has been dispatched are incorrect.
For an order posted on Friday 2nd December it shows the customer that the anticipated delivery period starts the next day even though the customer chose a delivery service of 2-3 business days.
It seems that the first date being shown is for the upgraded postal option and not the standard shipping option.
Many customers are getting confused as they truly believe their order will arrive in that time period.
on your listings I see
dispatch 9-12
deliver 10-17
so your first delivery date is next day,
word of warning, not sure which shipper you use, but if you are sending Royal mail, that is wildly optamistic
in your shipping profile, choose "other" and put in up to 10 weeks,