Processing Time: How long it takes from when the order is placed to when it is picked up by carriers.
Shipping Time: How long it takes the carrier to deliver your package after it is picked up.
Business Day: Monday-Friday, excluding major US Holidays.
For USPS we provide very broad estimated time ranges. USPS First Class, being the cheapest option, can be unpredictable and there are no guarantees.
USPS Priority can be delivered in 1-3 business days, depending on the distance from our warehouse. But again, it is not guaranteed to arrive in 1-3 business days.
UPS guarantees that Ground shipments will be delivered within 5 business days. UPS 2nd Day Air is, as it's name implies, guaranteed by the 2nd business day.