Like the wlan strength icons, the clocks and battery ramps draw multiple
glyphs at the same location to create multi-coloured icons. For them to
show up, you need my Bar Material Supplement font, which isn't published
yet because I haven't decided on a license nor on a way to host it.
Polybar doesn't support time zones yet, so I wrote my own date
displaying script. I think I'll keep it, it is more accurate: 0.02s
instead of up to 5s (configurable but higher frequency means more
CPU power used) latency.