AM/PM Time Format Check

This rule checks for improper formatting of time expressions using "am" or "pm" without periods. The rule promotes consistent and professional time formatting by ensuring that informal variations like "3pm" or "11am" are flagged in favor of more formal alternatives with periods (e.g., "3 p.m." or "11 a.m.").

Maintaining consistent time formatting is important for professional writing and clarity. Most style guides, including AP and Chicago, recommend using periods in "a.m." and "p.m." rather than the informal versions without periods.

Examples of what this rule flags:

• ❌ "The meeting starts at 3pm"
• ❌ "Wake up at 6am"
• ❌ "The store closes at 9pm"

These should instead be written as:

• ✅ "The meeting starts at 3 p.m."
• ✅ "Wake up at 6 a.m."
• ✅ "The store closes at 9 p.m."

The rule works by detecting any one or two digits followed by "am" or "pm" (with or without a space), regardless of capitalization.