When to when?

Imagine a world without effective medicine, surgery, or anaesthetics. A world devoid of plastics or synthetic fabrics. A world in which agricultural productivity was so low that animal products were a luxury to many. This was a brutal world of entrenched social inequality, almost devoid of labour-saving devices. A world in which even dim lighting was expensive during long, cold, winter nights.

Welcome to the Middle Ages.

When were the Middle Ages? > . 

Misconceptions about the Middle Ages - Dr Eleanor Janega & Jason Kingsley > .

"Scholars have advocated many different termini for our period, and there seems to be little agreement and indeed little basis for reasoned argument on these points. The Middle Ages begin, we are told, with the death of Theodosius in 395, or with the settlement of Germanic tribes in the Roman Empire, or with the sack of Rome in 410, or with the fall of the Western Roman Empire (usually dated A.D. 476), or even as late as the Moslem occupation of the Mediterranean. It ends … with the fall of Constantinople, or with the invention of printing, or with the discovery of America, or with the beginning of the Italian wars (1494), or with the Lutheran Reformation (1517), or with the election of Charles V (1519). Several reference works I have consulted simply assert that the Middle Ages ended in 1500, presumably on New Year's Eve. Yet another terminus often given for the Middle Ages is the so-called “Revival of Learning,” that marvelous era when Humanist scholars “discovered” classical texts and restored them to mankind after the long Gothic night. Medievalists must always smile a little over these “discoveries,” for we know where the Humanists discovered those classical texts—namely, in medieval manuscripts, where medieval scribes had been carefully preserving them for mankind over the centuries. … In view of all this disagreement over the duration of the Middle Ages, perhaps we should content ourselves with saying that our period extends from the close of the classical period to the beginning of the Renaissance. If classicists and Renaissance scholars don't know when their periods begin and end, then that is their problem."

Source:

Robinson, Fred. C. [1984]. “Medieval: the Middle Ages.” Speculum 59, pp. 745–56. (Presidential address to the annual meeting of the Medieval Academy of America, 1984.)

Cited here : Spade, Paul Vincent, "Medieval Philosophy", The Stanford Encyclopedia of Philosophy (Summer 2010 Edition), Edward N. Zalta (ed.), URL. 

[On the other hand, since there are no widely-accepted limits, it is much easier to remember 500 CE to 1500 CE.]