If you need to format a timestamp (and do so outside of the query) you need to use a regular expression:
mysql_connect("$DBHost","$DBUser","$DBPass") or die ("The database server is temporarily down for maintenance...");
$result=mysql("$DBName","SELECT entry_time FROM your_table");
while ($Nrow = mysql_fetch_row($result)) {
$Ntim=$Nrow[0];
$pieces=explode(":",$Ntim);
if ( ereg( "([0-9]{4})([0-9]{1,2})([0-9]{1,2})([0-9]{1,2})([0-9]{1,2})([0-9]{1,2})", $Ntim, $regs ) )
if ($Ntim != "") {
echo "$regs[2]/$regs[3]/$regs[1], $regs[4]:$regs[5]:$regs[6]";
}
}