Jess and I want to go on a day hike. Can you recommend one suitable for our abilities. (max about 5 hours)
Hmmm... depends how far you're willing to drive! Closest to Joburg, you've got Klipriviersberg and Suikerbosrand, both with options of about 10-12km well-marked trails with typical highveld scenery.
For some more impressive scenery, I'd head out to the Magaliesberg kloofs - Tonqani (non-technical) or Grootkloof (incl waterfall abseil). Otherwise there are a few lodges along the Magaliesberg ridge that have day hikes to the top. Rustig is one of them.
And then venturing into weekend-away territory, you can't go wrong with some of the hikes in the Northern Berg: Tugela Gorge or stuff at Cathedral Peak.
Thanks, definitely Magaliesberg - they sound good. Maybe later some more heavier hiking.