Check Leap Year
Check if a year is a leap year.
isLeapYear
Checks if a given year is a leap year according to the Gregorian calendar rules.
Leap Year Rules
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A year is a leap year if it is divisible by 4.
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However, years divisible by 100 are not leap years unless they are also divisible by 400.
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For example:
2000,2020,2400→ leap years ✅1900,2100→ not leap years ❌
Function Signature
isLeapYear(year: Numeric): boolean;Parameters
year: The year to check (can be number or numeric string)
Returns
true if the year is a leap year, false otherwise
Example Usage
playground.ts
Notes
- Handles both numbers and numeric strings
- Follows Gregorian calendar rules
- Works with negative years (BC dates)
- Returns
falsefor non-numeric inputs
Type Definition
type Numeric = number | `${number}`;Use Cases
- Date validation
- Calendar applications
- Age calculations
- Date arithmetic
- Financial year calculations
Key Points
- Accurate leap year detection
- Flexible input (numbers or numeric string)
Last updated: Fri, May 22, 2026 07:46:19AM (Coordinated Universal Time)