Best time: Defo pre-colonial era 19th century. This when all the major, major clan feuds began to take a rise. It was also extremely violent, with nomads traveling as far as 1000 miles to settle tribal scores and expand into different territory. Also, majority of the gabays were made in this time period.
Worst time: Without a doubt, the Somali civil war that began in the late 80's to 90's. Subxaanallah, many, many people died during that tragedy from all corners of Somalia. It was a bloody, horrific civil war which should be repeated ever again, hopefully. It's also the reason why we are on welfare in a western country.