Last night I took an evening hike (scramble) with the meetup.com group. Even though I had done the hike several times, it was different hiking in the evening. The refreshing breeze and a soft light cast a magenta glow on the rocks making for the perfect hike. Six of us hiked up and over Kraft Mountain descending into the wash. We started at 6 pm and were back to the cars around 8 pm. It had just got dark! There are lots of short hikes out of Calico Basin, perfect for hiking during the evening.
Other options are First Creek Waterfall, Las Vegas Overlook, and Oak Creek from 159. With all these hikes you do not have to drive the Scenic Loop, more hiking less driving!
So even if you work until 5 pm, you can still get in a fun hike before it gets dark!