Passing a decimal offset less than one without specifying a base date will always return the current date because the calculation time basis is always the beginning of the current date

The function offsetDate() returns a string with the native SQL functions to calculate future and past dates based on $isoDate in a portable fashion. If $isoDate is not defined, then the current date (at 12 midnight) is used.

The function returns the SQL string that performs the calculation when passed to Execute(). The value returned when the statement is executed is an ISO Date.

The function returns false if invalid parameters are provided.

The $offset parameter can be presented in 2 ways:

• As a decimal indicating the number of days where the decimal portion is the fraction of a day (e.g. 0.5 = 12 hours)
• As string in the format “float/24” where the floating point number is the number of hours

The $isoDate can be:

• A basis date in ISO format including a time portion, if a fractional calculation is required
• An SQL statement that produces an ISO date
• An SQL column if the method is to be used to calculate date offsets based on table values
• skipped or false for today

In Oracle, to find the date and time that is 2.5 days from today, you can use:

/*
 * get date one week from now  
 */
 
$fld = $conn->OffsetDate(7); 
/*
 * returns "(trunc(sysdate)+7")
 */
 
/*===
 *  get date and time that is 60 hours from current date and time 
 */ 
 
$fld = $conn->OffsetDate("60/24", $conn->sysTimeStamp); 
/*
 *   returns "(sysdate+2.5)"
 */  
 
$conn->Execute("UPDATE TABLE SET dodate=$fld WHERE ID=$id");

/*
* Get Date -273.5 Hours in the past
*/
$fld = $db->offsetDate("-273.5/24");
 
/*
* Returns " SELECT FORMAT(DATEADD(hour ,-273.5,GETDATE()), 'yyyy-MM-dd')"
*/

In this example we would use the statement to return a date 7 days forward from the current value of the column “delivery date”.

$newDeliveryDate = $db->offsetDate(7,'delivery_date');
 
$SQL = "SELECT $newDeliveryDate 
          FROM delivery_master 
         WHERE delivery_date = {$db->dbDate(date('Y-m-d')}".