What is the standard definition of afternoon and evening, including the specific time ranges? Who established this standard?

Afternoon and evening are defined time periods that can slightly vary depending on cultural and personal interpretations. Here are the generally accepted definitions:

Afternoon:

• Afternoon typically spans from midday to evening.
• The time range for afternoon is approximately 12:00 pm (noon) to 6:00 pm.
• Early Afternoon is from 12:00 pm to 3:00 pm, Mid Afternoon from 3:00 pm to 6:00 pm.

Evening:

• Evening usually commences around sunset or the end of the typical business day, which is typically between 5:00 pm and 6:00 pm.
• The evening time period ranges from approximately 6:00 pm to midnight.
• Late Evening/Night is typically considered to be from 9:00 pm to midnight.

It's important to note that these definitions can be flexible and overlapping. The transition from afternoon to evening often occurs around 6:00 pm, coinciding with dinner time.

The standard definitions for afternoon and evening have evolved over time and are commonly accepted without a specific attribution to an individual or organization.

References:

1. What Are Afternoon Hours (Explained: All You Need To Know)
2. What time is "afternoon" and when is "evening"?
3. Afternoon vs. Evening: It's Time to Differentiate | YourDictionary