Help with Variable Time Calculations

I would like to execute a scene four times a day during daylight at even internal. I am having trouble figuring out how to execute this using PLEG (or elsewhere if there is an easier solution).

Say the sun rises today at 7:05 am and sets at 6:35 pm. I want to calculate that there are 11 hours and 30 minutes of daylight today. Divide by 5 and there are 2:18 between each event. Meaning they will be at

9:23 am
11:41 am
1:59 pm
4:17 pm

I know how to do just sunrise or sunset or sunrise with an absolute offset of for example 30 minutes, but I am not clear how to do this calculation, store four variables with these times and then have the scene execute whenever the time matches one of these variables.

In case people are curious, this is to dispense food to my chickens at regular intervals when I am not at home.

Any help you can provide is appreciated.