[Users] relative times in modified between search on trac

Hello all,

our trac main page has a link "changed and still open" that finds all tickets that were touched in the last week.

The search involves having "1 week ago" in the "Modify between" field in the search mask. However it is impossible to put that string there using the web-interface it seems as clicking in the field pops up a calendar and one is only allowed to type in a data (eg "1" is accepted but not "month"). One can create any search one wants by directly editing the URL in the browser bar, but I am wondering if anyone knows of a more "official" way of achieving this.

Yours, Roland