Compare field date/time with system date and time in scheduled job

[Mishu]

To change state value to Open when custom date/time field (Reactivation Time) value matches with system date/time.

I am trying with below code, which is not giving the output.

Is there anything i am missing here ? Kindly Suggest 

var gr = new GlideRecord('sn_hr_core_case');
gr.addEncodedQuery('state=30^u_reactivation_timeISNOTEMPTY');
gr.query();
while (gr.next()) {

var reopen_date = new GlideDateTime(gr.u_reactivation_time);
var today_date = GlideDateTime();

if (reopen_date == today_date) {
gr.state = '10';
gr.work_notes = 'Updated State to Reopen';
gr.update();
}
} 

[Ankur Bawiskar]

@Mishu 

workflow why?