Thanks for the reply. I didn’t appreciate the important distinction between trigger channels and other types of channels. Your comment led me to Confusion between channels and channel triggers and its links that underscore the difference between and Event Channel and other channels.
It appears I can get what I was looking for (is it daylight?) by using the Astro bindings Sun Phase Name channel, which includes Daylight as one of the phases:
group phase
channel
name (String), values: SUN_RISE, ASTRO_DAWN, NAUTIC_DAWN, CIVIL_DAWN, CIVIL_DUSK, NAUTIC_DUSK, ASTRO_DUSK, SUN_SET, **DAYLIGHT**, NIGHT