Struct TimeHandler 

pub struct TimeHandler;

Time validation handler

Validates and canonicalizes time values. Supports multiple input formats:

• Single or double-digit hours: 0, 1, 01, 23 (converted to HH00 format)
• HH:MM format: Standard time with colon separator (e.g., “14:30”)
• HHMM format: Compact time without separator (e.g., “1430”)

All valid inputs are canonicalized to HHMM format (4-digit string) for consistent representation in topics and storage systems.

Implementations

impl TimeHandler

pub fn validate_and_canonicalize( value: &str, field_name: &str, ) -> Result<String>

Validate and canonicalize a time value to HHMM format

This method handles multiple time input formats and converts them to the standard HHMM format used throughout the system:

Supported Input Formats

1. Single or double-digit hours: “0”, “1”, “01”, “23” → “0000”, “0100”, “0100”, “2300”
2. HH:MM format: “14:30” → “1430”, “9:15” → “0915”
3. HHMM format: “1430” → “1430” (validated and normalized)

Arguments

• value - The time string to validate (in any supported format)
• field_name - Name of the field being validated (for error messages)

Returns

• Ok(String) - The time in canonical HHMM format
• Err(anyhow::Error) - Invalid time format or impossible time

Time Validation Rules

• Hours must be 0-23 (24-hour format)
• Minutes must be 0-59
• Leading zeros are added as needed for consistent 4-digit format