How to calculate years from two different date in ASP.NET C#

Question

I have Employee Admission Date which is stored in SQL table.

In the ASP.NET click event, i want to calculate and find the years from the Admission Date and Current Date.

For example,

Admission Date : 10-MAR-2023

Current Date : 28-APR-2024

condition is below.

If employee admission date is exactly more than 5(five years) from current date's

{

then the system should allow to enter for next admission

}

else (less than or equal to 5 years)

{

system should block the user to enter the admission date

}

How to generate simple logic for the above scenario...?

Answer 1

Hello @Gani_tpt

Since you did not clarify, if you are trying to implement this logic on the front-end, the backend, or on the SQL itself, you have 3 possibilities to consider.

C# backend:

DateTime currentDate = DateTime.Now;
int differenceInYears = GetDifferenceInYears(admissionDate, currentDate);
if (differenceInYears > 5)
{
    // Allow next admission
    // Your logic here...
}
else
{
    // Block user from entering admission date
    // Your logic here...
}

In SQL proc you may implement this.:

CREATE PROCEDURE CalculateDifferenceInYears
    @AdmissionDate DATE,
    @CurrentDate DATE
AS
BEGIN
    DECLARE @DifferenceInYears INT
    -- Calculate the difference in years
    SET @DifferenceInYears = YEAR(@CurrentDate) - YEAR(@AdmissionDate)
    -- Adjust for leap years
    IF MONTH(@AdmissionDate) = MONTH(@CurrentDate) AND DAY(@CurrentDate) < DAY(@AdmissionDate)
    BEGIN
        SET @DifferenceInYears = @DifferenceInYears - 1
    END
    -- Return the result
    SELECT @DifferenceInYears AS YearsDifference
END

and then implement it with your front-end like this.

using (SqlConnection connection = new SqlConnection("YourConnectionString"))
{
    connection.Open();
    using (SqlCommand command = new SqlCommand("CalculateDifferenceInYears", connection))
    {
        command.CommandType = CommandType.StoredProcedure;
        command.Parameters.AddWithValue("@AdmissionDate", yourAdmissionDate);
        command.Parameters.AddWithValue("@CurrentDate", DateTime.Now);
        using (SqlDataReader reader = command.ExecuteReader())
        {
            if (reader.Read())
            {
                int differenceInYears = Convert.ToInt32(reader["YearsDifference"]);
                // Your logic based on the differenceInYears here...
            }
        }
    }
}

I hope this answers your question.

Answer 2

Thanks for posting your question in the Microsoft Q&A forum.

Here is a sample implementation using C# within your ASP.NET click event handler:

protected void YourButtonClickEvent(object sender, EventArgs e)
{    
    DateTime admissionDate = DateTime.Parse("2023-03-10");
    DateTime currentDate = DateTime.Today;
    int yearsDifference = currentDate.Year - admissionDate.Year;
    if (currentDate.Month < admissionDate.Month || 
	      (currentDate.Month == admissionDate.Month && currentDate.Day < admissionDate.Day)
	   )
    {
        yearsDifference--;
    }
    if (yearsDifference > 5)
    {
    }
    else
    {
    }
}

---

Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful

Answer 3

Check if the current date is greater than the admission date + five years.

This code is straight forward in any language.

SQL

DROP TABLE IF EXISTS #DateEx;
GO
CREATE TABLE #DateEx (
	ID			INT IDENTITY,
	MyDate		DATETIME
)
DECLARE @DateNow DATETIME = GETDATE()
INSERT INTO #DateEx(MyDate)
VALUES	(DATEADD(YEAR, -1, @DateNow)), 
		(DATEADD(YEAR, -2, @DateNow)),
		(DATEADD(YEAR, -5, @DateNow)),
		(DATEADD(YEAR, -6, @DateNow))

SELECT  MyDate, 
		GETDATE() [Now],
		CASE WHEN DateAdd(YEAR, 5, MyDate) <= GETDATE() 
			THEN 'Greater than or equal to 5 years' 
			ELSE 'Less than 5 years'
		END AS [Result]
FROM #DateEx

C#

DateTime myDate = new DateTime(2023, 3, 10);
DateTime myDatePlus5Years = myDate.AddYears(5);
if (myDatePlus5Years <= DateTime.Now)
{
    Console.WriteLine("Greater than or equal to 5 years");
}
else
{
    Console.WriteLine("Less than 5 years");
}

Another approach is subtracting 5 years from today's date then comparing to the admission date. Either way, this is a basic addition/subtraction math problem.