Struct DateHandler 

pub struct DateHandler;

Date validation and canonicalization handler

Supports multiple input date formats:

• YYYY-MM-DD: ISO 8601 standard format (e.g., “2025-12-25”)
• YYYYMMDD: Compact format without separators (e.g., “20251225”)
• YYYY-DDD: Day-of-year format (e.g., “2025-359” for December 25th)

All valid input formats are canonicalized to the format specified in the schema configuration, ensuring consistent representation across the system.

Implementations

impl DateHandler

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

Validate and canonicalize a date value according to schema requirements

This method performs comprehensive date validation:

1. Attempts to parse the input using multiple supported formats
2. Validates that the date is actually valid (e.g., no February 30th)
3. Converts to the canonical format specified in the schema

Arguments

• value - The date string to validate (in any supported format)
• canonical_format - Target format for canonicalization (“%Y%m%d” or “%Y-%m-%d”)
• field_name - Name of the field being validated (for error messages)

Returns

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