This was taken sometime after 2:00 PM if I remember right, likely before 2:30. However I'm not a regular visitor (this was only like my 3rd or 4th visit ever) so I don't know if there's a usual time when they're active and I also only saw them once so for all I know they were active the entire day.
@Lucas Lang The zoo's trio is pretty active all times of the day I've found. Earlier in the day is probably best but I seldom see them not moving around these days.