The best time to go is Nov-Mar, and the waterfall is usually only "flowing" after a rainstorm, so plan accordingly. Night hiking here is an option and should take about ~2 hours. It is $6 parking per car.
So to fully enjoy the theme of this hike, make sure to try and go right after a rain. But also know that since this is a pretty easy hike, you will won't be the only one there. This is also a great hike/ waterfall to do with someone that is new to desert hiking, since it is relatively easy and there isn't a lot of elevation gain. The trail is clearly marked with interpretive signs pointing out and describing various formations and things to see. A pretty awesome hike after a rain.