TP-Link's Kasa equivalent of the S20 plug-in switch has sunset and sunrise time events, which follow the local dusk and dawn times.
This is very useful for lighting (internal and external) - can we get this added to E-WeLink?
Of course should this be implemented. Every serious home-automation-app (eg WeMo for Belkin) has it.
I used in the past a system of Sunrise/Sunset functions on previous application. It worked out the time from the system date and you gave it your location (latitude). That was several decades ago but with the invention of the smart phone and the fact that it already knows your location, the function would not appear very difficult compared with the other eWelink time functions available.
With home automation, I would think it very useful for home security lighting. It also adapted for daylight saving although smart phones nowadays already accommodate for that.