Date arithmetic between dates?

Previously, something like the following would be easily parsed and would return a number of days, plus a number of months, weeks, and days between these dates

Feb 4, 2016 - Feb 4, 1906

But recently this stopped working and produces unhelpful parse errors.

Hi Toni,

You need to put an = before your input dates in order to recognize Natural-language inputs with Mathematica.

Not working in Wolfram Alpha