Edit this sentence in a way that provides more detail and clarity:
The bus left at 8am.
The public transportation bus departed from the station promptly at 8:00 AM according to schedule.
Complete the following task based on the instruction and optional input provided.### Instruction:
Edit this sentence in a way that provides more detail and clarity:

### Input:
The bus left at 8am.

### Output:
The public transportation bus departed from the station promptly at 8:00 AM according to schedule.