I agree that AB's search facility is far from great. For that reason I sometimes use a 'site specific' Google search to find posts on AB.
For example, the following search string will find all AB posts with the word 'Boris' in them:
boris site:theanswerbank.co.uk
[If I wanted to refine that search to only find posts that didn't include 'Johnson', I could use the following search string]:
boris -johnson site:theanswerbank.co.uk
Once I've done that, I can then click on 'Tools' and change 'Any Time' to show results from the past hour, day, month or year.
Alternatively, if I only wanted to search for results from, say, 2015, I could select 'Custom range' and then define the start and end dates for my search as 1/1/2015 and 12/31/2015 respectively. [Note that, annoyingly, Google uses the US date format].