Making timed challenges more obvious

I love joining timed challenges that others have started, the problem is not knowing if a challenge is timed or untimed.

For example, here on the activities page for the US Capitals map:


Would it be possible to program in the length of the challenge into the description, so "Es played a challenge on US Capitals and got 13 274 points" would become
"Es played a 5 min challenge on Us Capitals...."

Or even if there was a way to indicate whether it was timed or not, would be nice.