how to check two dates between from-date and to-date

Question

I have two dates from-date & to-date .

I have to compare them from existing dates shown below, whether any of the day fall between them or not using php?
i can do for single date checking ,but i am confuse for the two date checking.

Example: i have to check these dates:-> from= 15 March 2013 & 15 April 2013 between the following dates whether any days falls in between these two date or not.

following data from db table

 #       from date            to-date
-----------------------------------------
1     01 April 2013         30 April 2013   //here we will find as falling
2     01 May 2013           15 May 2013   
3     01 June 2013          20 June 2013

Currently,in my mind not even a single logic is coming to try. Please give me any logic or suggestions regarding this issue..

Answer 1

The simplest way to compare dates is to convert them to a unix timestamp

Because the unix timestamp is an integer, you can simply use relational operators to compare them.

Example

// set some example data
$referenceDate = '01 April 2013';
$fromDate = '01 January 2013';
$toDate = '01 June 2013';

// convert dates to timestamps (strings to integers)
$referenceTimestamp = strtotime( $referenceDate );
$fromTimestamp = strtotime( $fromDate );
$toTimestamp = strtotime( $toDate );

// isBetween is Boolean TRUE if reference date is greater or equal fromDate and smaller or equal toDate
$isBetween = $referenceTimestamp >= $fromTimestamp and $referenceTimestamp <= $toTimestamp;

EDIT 1

To actually answer your question:

You have two ranges you need to test for overlap, this question has been answered here What's the most efficient way to test two integer ranges for overlap?

// our two ranges overlap if the following conditions are met
$dateRangeOverlaps = $referenceFromTimestamp <= $toTimestamp and $fromTimestamp <= $referenceToTimestamp;

Answer 2

Please try the code,

    $ourdate = strtotime('1 April 2013'); // Your date which is to be checked

    $from = strtotime('15 March 2013'); // From date
    $to = strtotime('15 April 2013'); // To date

    if ($ourdate >= $from && $ourdate <= $to)
    {
      echo "Date falls";
    }
    else
    {
    echo "No Date falls";
    }

If you need to check several dates, pass it as an array, like below...

   $i=0;
   $dates= array("11 April 2013","16 April 2013");
   foreach($dates as $ourdates)
   {
    $ourdate= strtotime($ourdates); //Your dates to be checked
    $from = strtotime('15 March 2013'); // From date
    $to = strtotime('15 April 2013'); // To date

          if ($ourdate >= $from && $ourdate <= $to)
              {
                 $i++;
              }
    }
    if($i>0)
    {
    echo "Date falls";
    }
    else
    {
    echo "No Date falls";
    }