Performing query by updated or last updated option

I’m currently running RT 3.4.2, and I have the need for a query based on
updated or last updated (forgive me, but I do not know the difference).
I have entered various formats in this form field, such as:

Mon Jun 05
24 hours

However, I don’t get any results back from the query. I know plenty of
tickets exist that were updated in this period.

Thanks in advance for any thoughts/experiences!

Ian Tyndall