Static Method is_gregorian_leap_year

Determines whether a given year is a leap year according to the rules of the Gregorian calendar.

Description

This static method checks if the provided year qualifies as a leap year based on the standard Gregorian calendar algorithm. This is distinct from the Persian calendar leap year rules.

The Gregorian leap year rules implemented are:

1. A year is a leap year if it is evenly divisible by 4.
2. However, if a year is evenly divisible by 100, it is not a leap year...
3. Unless that year is also evenly divisible by 400, in which case it is a leap year.

This method is useful for contexts where interactions or conversions between Persian and Gregorian dates occur.

Arguments

• year: The Gregorian calendar year (e.g., 1900, 2000, 2024) as an integer type (e.g., i32) to be checked.

Returns

• true if the specified year is a leap year according to the Gregorian calendar rules.
• false otherwise.

Note: This method performs a straightforward calculation based on divisibility rules and does not typically return errors.

Examples (Rust)

use parsidate::ParsiDate; // Assuming ParsiDate provides this static method

// --- Leap Year Cases ---

// Divisible by 400 -> Is a leap year
assert_eq!(ParsiDate::is_gregorian_leap_year(2000), true);
assert!(ParsiDate::is_gregorian_leap_year(1600));

// Divisible by 4 but not by 100 -> Is a leap year
assert_eq!(ParsiDate::is_gregorian_leap_year(2024), true);
assert!(ParsiDate::is_gregorian_leap_year(1996));
assert!(ParsiDate::is_gregorian_leap_year(2020));


// --- Common Year Cases ---

// Divisible by 100 but not by 400 -> Is NOT a leap year
assert_eq!(ParsiDate::is_gregorian_leap_year(1900), false);
assert!(!ParsiDate::is_gregorian_leap_year(1700));
assert!(!ParsiDate::is_gregorian_leap_year(1800));
assert!(!ParsiDate::is_gregorian_leap_year(2100));

// Not divisible by 4 -> Is NOT a leap year
assert_eq!(ParsiDate::is_gregorian_leap_year(2021), false);
assert!(!ParsiDate::is_gregorian_leap_year(2023));
assert!(!ParsiDate::is_gregorian_leap_year(1997));

// --- Edge Cases (if applicable, though rules are clear) ---
// Check year 0 or negative years if relevant to the type,
// although calendar years are typically positive.
// Assuming standard positive year input:
// assert_eq!(ParsiDate::is_gregorian_leap_year(4), true);
// assert_eq!(ParsiDate::is_gregorian_leap_year(100), false);