Two dates within a year of each other

Question

I got two dates, how do I check if both dates does not exceed over one year?

Short question! :-)

Answer 1

if (Math.Abs((d1 - d2).TotalDays) < 365)

---

Edit: This should account for leap years better.

if ( d1 <= d2 && d1.AddYears(1) >= d2 || d2 < d1 && d2.AddYears(1) > d1)

Update:
I like @JDunkerley's solution better:

if (d1 < d2 ? d2 < d1.AddYears(1) : d1 < d2.AddYears(1))

Answer 2

if (year(date1) == year(date2))
{
   //true
}
else
{
   //false
}

Answer 3

I give you a little example:

DateTime startTime = DateTime.Now;

 DateTime endTime = DateTime.Now.AddSeconds( 75 );

 TimeSpan span = endTime.Subtract ( startTime );
 Console.WriteLine( "Time Difference (seconds): " + span.Seconds );
 Console.WriteLine( "Time Difference (minutes): " + span.Minutes );
 Console.WriteLine( "Time Difference (hours): " + span.Hours );
 Console.WriteLine( "Time Difference (days): " + span.Days );

Answer 4

TimeSpan ts = Date1.Subtract(Date2);

if(ts.Days > 365)
{
// Over a year.
}

Answer 5

That depends on the date format.

• If you have two timestamps, you may calculate the difference between them.
• If you have two specific dates in a known format, you simply compare the year attributes as strings.

Answer 6

If they're both in DateTime structures, then you can just subtract the two to get a Timespan structure. The Timespan structure has a Days property which you can look at.

So you'll have something like:

if(Math.Abs((date1 - date2).Days) <= 365) ...

Answer 7

This is the same question as "how do I calculate someone's age".

Blatantly stealing the answer from there and modifying it for use:

public static bool DatesAreWithinOneYear(DateTime date1, DateTime date2)
{
    DateTime startDate = date2 > date1 ? date1 : date2;
    DateTime endDate = date2 > date1 ? date2 : date1;

    int years = endDate.Year - startDate.Year;
    if (endDate < startDate.AddYears(years))
    {
        years--;
    }
    return years < 1;
}

Answer 8

If necessary, swap t1 and t2 so that t1 <= t2

if(t1.AddYears(1) >= t2) {
    // t1 is within a year of t2
    return true;
} else {
    // t1 is not within a year of t2
    return false;
}

Answer 9

Takes into account leap years, etc.

if (    Math.Abs((d1 - d2).TotalDays)
     <= Math.Abs((new DateTime(d1.Year, 1, 1)
                  - new DateTime(d2.Year, 1, 1)).TotalDays))
{
   // Within 1 year
}