launchpad accepts a date in the past for 'expires' field in team membership approval

Hi,

When accepting a new member in a team, I made the mistake of selecting 'today' as expiry date (I was trying to get an year from approval instead of an year from when he applied) and after submitting, Launchpad showed the member as approved and the expiry date as '22 hours ago'. This is strange, a member should either be approved or expired, not both at the same time.

Steps to reproduce (using sample data):
1. Open http://launchpad.dev/~ubuntu-team/+member/name12
2. Click the calendar widget and choose today
3. Click Approve
4. The approved person will show up in the active listing but in the expires column says: "20 hours ago"