Does exactly what it says! Question for the developer: would it be possible in a future update to include a toolbar button that could be clicked to toggle back and forth between the two set themes? On very dark winter days, even though sunset is still several hours away, my office gets so dark that I find that I need to activate the dark theme early. A one-click solution for that scenario would be highly appreciated! Either way, thank you for this wonderful extension.

exactly what i needed, thanks

Working great. That's exactly what I was looking for. I love it. Thank you.

Perfect

More than just time-based : This one's actually can sync with OS settings, so it helps cover one of Firefox's drawback. Very well done, light, and responds quickly.