Quick fix: Please add a timestamp to the show_badges page.
Slow fix: This is the real Request For Enhancement, for people that are crunching for badges.
On the show_badges page, add a column that displays the approximate time remaining (in integer days, rounded up) to accumulate enough credit to reach the next badge level for each subproject, based on "recent credit rate" for each badge. Rather than show enormous time estimates, cut it off at 365 days and show "> 1 year". Use a blank if the "recent credit rate" is 0.
"Recent credit rate" is a daily rate for each subproject. These rates divide the credit needed, excluding pending credit, to produce the estimated days.
This feature would be most valuable for subprojects having shorter deadlines, but grossly inaccurate for subprojects with long validation times, low resource commitment, insufficient credit history, and of course conjectures whose solution is "imminent". A disclaimer should be enough to warn users that are seeking instant gratification or guaranteed badges.