Marking records that haven't been update on a specific date

HI,

I'm building a Creator app, with 2 forms "Work Orders" and "Helper". Every day, an excel sheet is uploaded / imported to the Helper form, where each row is added as new record.

One column of the excel sheet is a unique number "WO number" and is saved in a "WO Number" field

For each new record, a workflow compares if the record exists in the "Work Orders" Form, matching the "WO number" field / column.

If the "WO number" from "Helper" form exists in the "Work Order" form , I update each field that is different. (ie I update the entire row if needed).

If the WO number isn't found, I add the record to the Work Order form.

Now, here is my problem: Once all records from Helper form have been added or update in "Work Order" form, a Deluge script is used. I need to check a "Archived" checkbox field of every record that haven't been update today... I don't know how I can find untouched record ! I don't know what can be the criteria to something like:

untouched_records = Work_Orders[modified_time is before today]

Any clue ? I need to evaluate record because they havent been update today. Or may be I should think the way around ? but how.

Let me know if I'm not clear.

Thank you for your help.