suno

suno refers to light and some sources of light. The prototypical suno is the sun.

tomo ni la suno tu li lon.

There are two lights in this room.

suno also refers to days. This is one of the most common cross-linguistic metaphors, with 412 realizations in DatSemShift 3.0.

suno tu la mi lon ma Putape.

I was in Budapest for two days.

Speakers will sometimes say tenpo suno to disambiguate this usage or emphasize the aspect of time.