I'm running a php script that retrieves the AVG of some data from 1 previous day:
$yesterday1=date('Y-m-d H:i:s', strtotime('-1 day'));
$strSQLYesterDay1=" SELECT AVG(Temperature) As TAverage1 FROM minute WHERE ";
$strSQLYesterDay1=$strSQLYesterDay1. "DateTime LIKE '" . substr ($yesterday1,0,10)."%'";
What to I change in this php/sql script so that instead of "1 day" ago, it's "1 hour" ago?