There seems to be a bug in doing searches on date ranges - specifically in Advanced Search and in Find Contributions. We're using Drupal and Civi 4.6.2.
When I type into Adv Search's Member Since date range fields OR Find Contribution's contribution date range fields only 2 digits for the year (1/1/14) I get a nonsensical number of records back. No error msg, just an obviously wrong set of data. I confirm by looking at several records but they do not match the date range in either Member Since or Contrib Date.
However, when I type in all four year digits, then I get the expected results.
I have tested this in the demo Civi and received the same results for both - only 2 digits gets bad results, 4 digits gets correct one.
I used to be able to type in only 2 digits (since we started using Civi in 11/12).
Please add in an error message or change the field instructions.