The History of the period from the end of Medieval period to 1950 or so is often referred to as Modern History. The period from 1950 to present under this scheme is termed post-modern, or contemporary history.
Supposedly the contemporary period is supposed to designate a period still largely within living memory, and thus the boundary will move forward over time. However, personally I think the dividing line at 1950 is actually a very good place to keep it, so I hope it stays there. A typical person living in 1940 was not living a life too much different than one in 1500. There were more machines around in 1940, but people still related to each other in the same ways. If you needed to know something, you asked around to find the local expert, or you went to the library. If you needed to communicate with someone, most likely you wrote a letter. Today we have information at our fingertips that puts the most magnificent 20th Century library to shame, and we expect to be able to communicate with anyone we want instantly.
So personally I think split at 1950 is a good one. I don't like the names so much ("contemporary" is more recent than "modern"? What brand of English is this?), so I'd prefer if we used something more like Renaissance and Computer Age, but the current time split is good.