Exactly what benefit does leaving them during daylight hours bring? My company subscribes to the 'as required' philosophy, and I turn them off during good viz in daylight hours on the basis that they serve no benefit to flight safety.
However, what I cannot understand in my company is the speed with which people turn off the wx radar. My personal thought is that the radar should be on at all times unless good clear visual conditions prevail, ie on always at night and in imc.