When your FedEx delivery date changes to pending it can mean that there was something that happened to cause a delay in the package delivery.
There may be severe weather events causing delays or the package may have not gotten on the truck or plane in time for delivery.
The package for FedEx goes through sorting facilities and is then loaded onto trucks or planes to be delivered to other sorting facilities until it reaches your destination.
Sometimes you'll get an expected delivery date when the shipping label has been created and then once FedEx has the package it updates to a new closer delivery date.
I would wait another day and then by the next day the delivery date should update to give you an expected delivery date that should be accurate.
Most FedEx ground packages take around 3 to 4 days to deliver but if it's Smart Post through FedEx then it can take a week to 14 days to get the package.
Most times FedEx does deliver your packages on the expected delivery date.
However there have been times where a package was delivered to me by FedEx a day before the expected delivery date.
Also sometimes delays can happen such as severe weather that may cause a day or two delay in the delivery date of your FedEx package but it's rare that it happens.
Most times you will get your package from FedEx on the expected delivery date.
Some packages require a signature for the FedEx package and some packages will just be left at your door.
If you're gone and the FedEx package requires a signature then the FedEx driver will leave a door tag where you can sign the door tag for your signature and they will release the package.