Mass action: remove published until date

[mrbaseman]

I have two NWI pages, one for the current postings, and another one as archive. I'm using time based publishing on the main page, and from time to time I move the older posts to the NWI section on the archive page. This works well using the mass action "move posts to another NWI section".
On the archive page, however, I have to remove the "published until" date, which is usually in the past for these entries that I select for moving. So it would be quite useful to clear the "published until" date in a mass action rather than clicking on each post, remove the date and save each one separately.
I guess it shouldn't be too complicated to implement. I have assigned myself, and maybe I find the time soon, and if not, this issue is at least a reminder.