初日

1. Origins, structure, and basic meaning

• Structure: 初日 is read as しょにち and can mean “first day” or “opening day”, depending on context.
• Basic usage: The examples show the first day of a course and the opening day of an exhibition.

2. Common pitfalls and similar expressions

• Distinguishing senses and uses
  • It means the first day of an event or schedule and differs from 初めて, which marks doing something for the first time.