After I updated my "0-day handling time (with standard shipping)" shipping cut-off time in Amazon Order Fulfillment Settings to 1:00 AM (the earliest option provided by Amazon), I assumed orders received after this time would have a Ship By date of the next business day.

However, Amazon actually interpreted the 1:00 AM setting as a cut-off time of 11:59 PM local time, meaning Amazon was now requiring all orders placed before midnight to ship the same day. This misunderstanding caused issues because:

• My intention was for the earliest possible daily cut-off—1:00 AM—to trigger a next-day Ship By date for orders placed after that time.
• But instead, Amazon's system assigned same-day Ship By dates for all orders placed after the setting change, even those placed just before midnight, significantly affecting delivery expectations.

To clarify:

• Expected behavior: Setting the pick-up availability to 1:00 AM would plainly mean any orders placed after 1:00 AM today would have a Ship By date of the following business day.
• Actual behavior: Amazon applied an 11:59 PM local time cutoff, causing all orders placed up until midnight to have a Ship By date of the same day.

This discrepancy impacted both handling times and customer delivery estimates negatively, due to Amazon's unexpected interpretation of the earliest possible cut-off time.