How to set fields value in Views PHP module?
First you need to load the node

$node = node_load($data-&gt;nid);


then you can either access

$value=$node-&gt;field_name['und'][0]['value'];


or assign

$node-&gt;field_time['und'][0]['value'] = $value


values to the node items. You may need to print out the content of the $node object to see the actual field_name 

$node_r = print_r($node, true);
watchdog('NODE PRINT OUT', "$node_r");


then view it in the recent log mesages

admin/reports/dblog


Ensure the DBlog (Database logging) core module is enabled