Twice a day - an hour after sunrise and an hour before sunset there is a little bit of magic in the air. A perfect time for photography!
It's a time where the light foes not cause any harsh shadows. It flatters your subjects and adds just that bit extra to your photos. Unfortunately, it can mean getting up early and walking to your destination in the dark to capture the moment of beauty but it it usually worth it.
At mid-day the light can be harsh causing shadows where you don't want them. As well as causing over exposure. But for some subjects you don't need the golden hour! Use a reflector to control the light that you have on offer. An overcast day can dampen the light and even change the way a subject looks.
Ultimately use the light which best suits you but don't forget the little bit of magic at the beginning and end of the day!