This PR adds a new date utility function that formats dates into human-readable relative time strings.

Key Features:

• Converts dates to "X time ago" or "in X time" format
• Supports multiple time units (years, days, hours, minutes, seconds)
• Handles both past and future dates
• Returns "just now" for timestamps within last second
• Includes usage examples

Example outputs:

• Past date: "2 years ago"
• Future date: "in 3 months"
• Recent: "just now"