ISLEAPYEAR

Tests if a date is in a leap year.

Syntax:

ISLEAPYEAR(date)

Returns 1 if date lies in a leap year, and 0 otherwise.

Example:

ISLEAPYEAR("2012-05-24")

returns 1; 2012 is a leap year.

Application:

Calculating Employee Tenure

Scenario: A company's HR department needs to calculate the exact tenure of its employees for a long-service award program. The program gives an employee a special bonus after they have worked for the company for exactly 10 years. The company needs to accurately determine the 10th anniversary date, which requires knowing if the start date spans a leap year.

Function: The ISLEAPYEAR(year) function returns a boolean value (TRUE or 1) if the year is a leap year and FALSE or (0) otherwise.

Problem: Employee Jane Doe started on February 29, 2012. Her 10-year anniversary should be on February 29, 2022. However, 2022 is not a leap year. The company's payroll system needs to correctly identify that her anniversary date should be adjusted to March 1, 2022, to ensure she receives her bonus on time. The ISLEAPYEAR function is a crucial part of the logic.

Table:

	Employee ID	Start Date	Start Year	ISLEAPYEAR(Start Year)	End Date (10-Year Anniversary)	Adjustment Needed?
	A	B	C	D	E	F
1	1001	1/15/2010	2010	FALSE	1/15/2020	No
2	1002	3/20/2011	2011	FALSE	3/20/2021	No
3	1003	2/29/2012	2012	TRUE	2/28/2022	Yes
4	1004	7/1/2014	2014	FALSE	7/1/2024	No
5	1005	4/10/2016	2016	TRUE	4/10/2026	No

Logic Explanation for Employee 1003:

The system takes the Start Date (2012-02-29).
It calculates the 10-year anniversary by adding 10 years to the Start Year (2012 + 10 = 2022).
The system checks if the new year, 2022, is a leap year using ISLEAPYEAR(2022). The function returns FALSE.
Since 2022 is not a leap year, it does not have a February 29th. The system's logic needs to handle this "date overflow." A standard business rule is to move the date to the next valid day, which is March 1, 2022.
If the anniversary year were a leap year (e.g., if the employee had started on Feb 29, 2016, their 10-year anniversary would be Feb 29, 2026), no adjustment would be needed because ISLEAPYEAR(2026) would return TRUE.