Physically settled trades have a delivery time or period specified in the terms (details) of the trade

Delivery is the physical act of delivery of the traded commodity at the location and time specified in the trade details

Detail

The act of physical delivery is made in different ways according to the commodity:

Gas:

Location is some specified point on the gas pipeline network

Time is usually specified at daily granularity, a trade may cover one or more days, months, quarters or seasons

Power (electricity):

Location is some specified point on the electricity grids

Time may be specified at quarter hour or above granularity

Oil & Coal:

Location is specified as a port, or group of ports in the trade details - the specific port or docking location is specified later by mutual agreement within the terms of the trade.

Time is usually specified at monthly granularity - the specific dates being agreed later as shipments become clear 

In general:

Gas and power delivery continuously throughout the delivery period, and the delivery volume is often specified as a rate of delivery

Megawatt (MW) for power - remember one MW flowing for one hour is a Megawatt.Hour (MWh)

Therms per day (therms/day) for gas

Oil, coal, LNG and most other commodities are delivered in discrete consignments at mutually agreed points in time during the delivery period