This is a very simple fix, easily done with a Villager with a Custom Name.
First, summon a Villager of the desired profession
/summon minecraft:villager ~ ~ ~ {Profession:X,CustomName:"Test",CustomNameVisible:0}
This will summon a Villager named Test.
Now place an always active, unconditional, repeating command block with this command inside:
/effect @e[type=Villager,name=Test] ID Time Amplifier
Replace the name of the villager with whatever you choose, making sure it is contained within the quotations (except when using /testfor, no quotes needed), and replace the ~ ~ ~ with the desired location of the Villager. The profession (X) can be replaced with any of the professions of a Villager (5 is an Illager), but the value has to be a number, not a word. This works with any version, not just 1.11.
Caution: the 5 in 1.11 is an Illager, but in anything below 1.11 it changes back to the first Villager form. For more information, view Skylinerw's link for 1.8, 1.9, and 1.10 NBT tag changes.