How to use date_modified in logic hook [date() not working]

I am trying to use a process_record logic hook to highlight records when the date modified is more than 2 days ago.

I.E we want to be able to see at a glance which records haven’t been touched recently so we are reminded to keep them updated.
As my suitecrm date format uses the british format (with date first then month) this needs to be converted to american format first before being converted to time with strtotime (as I found out recently).
I used date() and this worked fine with due_date, but when passed with date_modifed it returns 31/12/1969 for every record!

I have tried looking into this but I’m told it means the data isn’t being passed through correctly, but nothing I try works.

Any ideas?